Flex overlay. Correct display of flex

There is a site in the central part of which there are product cards, which are flex containers.

// такой же код, что и код выше - только для черных пунктов меню типа Моноблоки 
        let categoryflag='';
            $('.submenu__title a').on('click', function (event) {
                event.preventDefault();
                console.log('Inner check');             
                categoryflag=event.target.innerHTML;
                subcategoryflag=categoryflag;
                console.log(categoryflag);
                $.ajax ({
                    method: 'POST',
                    url: '../php/ajaxsubcategory1.php',
                    cache: false,                   
                    data: {categoryflag: categoryflag, subcategoryflag: subcategoryflag},
                    dataType: 'json',
                    complete: function(data) {
                        console.log(data.header);
                        console.log(data.countrecords);
                    },
                    success: function (data) {
                        console.log('check');
                        console.log(data);
                        $('.rightmenu').html(data.result.msg);
                        let centeroutput='<div id=\"topcenterarea\">'+'<h1>'+data.result.header+' '+data.result.countrecords+' товара' + data.output[0]['screendiagonal'] + '</h1>'+'</div>';
                        
                        
                        productcardsoutput='';
                        // productcard='<div class="ProductCardBlock">';
                        
                        
                        for (let i=0; i<data.result.countrecords; i++)
                            {
                                productcard='<div class="ProductCardBlock">';
                                productcard+='<div class="ProductImage">';
                                productcard+='<div id="ImageWrapper">';
                                productcard+='<img class="ProductPicture" src='+'"../images/'+data.output[i]['imagepath']+'">';
                                productcard+='</div>';
                                productcard+='</div>';
                                productcard+='<div class="ProductDescription">';
                                productcard+='<div class="ProductName">' + data.output[i]['monoblockname'] +', ' + data.output[i]['color']+ '</div>';
                                productcard+='<div class="ProductScreenParams">'+ 'Диагональ/разрешение  ' + data.output[i]['screendiagonal'] + '/' + data.output[i]['resolution'] + 'пикс.' +'</div>';
                                productcard+='<div class="ProductCpuType">'+ 'Тип процессора  ' + data.output[i]['cputype'] +'</div>';
                                productcard+='<div class="ProductCpuFrequency">'+ 'Частота процессора  ' + data.output[i]['frequency'] +'</div>';
                                productcard+='<div class="ProductRAM">' + 'Оперативная память (RAM)  ' + data.output[i]['ramsize']  +'</div>';
                                productcard+='<div class="ProductVideoCard">' + 'Графический контроллер  ' + data.output[i]['videocard']  +'</div>'
                                
                                if (data.output[i]['memorytype']=='SSD') {
                                    productcard+='<div class="ProductDisksAndDrives">' + 'Объем SSD  ' + data.output[i]['sizememorydata']  +'</div>';
                                }
                                else if (data.output[i]['memorytype']=='HDD') {
                                    productcard+='<div class="ProductDisksAndDrives">' + 'Объем HDD  ' + data.output[i]['sizememorydata']  +'</div>';
                                };
                                
                                productcard+='</div>';
                                productcard+='<div class="ProductBuyPart">'+ '<button type="submit" class="ProductAddToBasket" value="В корзину"></button>' +'</div>';
                                // productcard+='<div class="ProductScreenParams">'+ 'Диагональ/разрешение ' + data.output[i]['screendiagonal'] + '/' + data.output[i]['resolution'] + 'пикс.' +'</div>';
                                
                                
                                // productcard+='</div>';
                                // productcard+='</div>';
                                // productcard+='</div>';
                                // productcard+='</div>';
                                productcard+='</div>';
                                productcardsoutput+=productcard;
                            }
                        
                        centeroutput+=productcardsoutput;
                        
                        /*$('.centerarea').html('<div id=\"topcenterarea\">'+'<h1>'+data.header+' '+data.countrecords+' товара'+'</h1>'+'</div>');*/ 
                        $('.centerarea').html(centeroutput);

                        //expandCollapsedFunction();
                }
            }
            );
        }
        );

.ProductCardBlock {
    width: 100%;
    display: flex;
    flex-direction: row;
    justify-content: space-between;
    height: 311px;
}

.ProductCardBlock .ProductImage {
    /*width: calc(191.5/931.75)*100%;*/
    width: 10%;
    height: 100%
    
}

.ProductCardBlock .ProductImage .ProductPicture {
    margin-left: 15px;
    margin-top: 20px;
    margin-right: 5px;
    
}

.ProductCardBlock .ProductDescription {
    width: 60%;
    margin-top: 20px;
    font: 14px Roboto, Tachoma, Arial, sans-serif;
}

.ProductCardBlock .ProductDescription .ProductName {
    margin-bottom: 15px;
    font: 16px Roboto, Tachoma, Arial,sans-serif;
}

.ProductCardBlock .ProductDescription .ProductScreenParams {
    font: 14px Roboto, Tachoma, Arial,sans-serif;
    padding-bottom: 5px;
    margin-bottom: 0;
}

.ProductCardBlock .ProductDescription .ProductCpuType {
    font: 14px Roboto, Tachoma, Arial,sans-serif;
    margin-bottom: 5px;
}

.ProductCardBlock .ProductDescription .ProductCpuFrequency {
    font: 14px Roboto, Tachoma, Arial,sans-serif;
    margin-bottom: 5px;
}

.ProductCardBlock .ProductDescription .ProductRAM {
    font: 14px Roboto, Tachoma, Arial,sans-serif;
    margin-bottom: 5px;
}

.ProductCardBlock .ProductDescription .ProductVideoCard {
    font: 14px Roboto, Tachoma, Arial,sans-serif;
    margin-bottom: 5px;
}

.ProductCardBlock .ProductDescription .ProductDisksAndDrives {
    font: 14px Roboto, Tachoma, Arial,sans-serif;
    margin-bottom: 5px;
}

.ProductCardBlock .ProductBuyPart {
    width: 30%;

}

.ProductCardBlock .ProductBuyPart .ProductAddToBasket {
    margin: auto;
    padding: 0;
}

There is a code that displays these flex containers (they consist of an image - ProductImage, product characteristics - ProductDescription and a button - ProductAddToBasket, centered inside the ProductBuyPart block).

As a result, I get the following page in the browser

nobutton

Tell me how to get flex items to display correctly (some may have fixed widths). The picture should have 10% of the width of the product card, the description of the product - 60%, and the block with the button - 20%. (it is also possible to distribute the widths of the elements - 200px per picture, and for the product description and the button - 60% and 40% of the rest of the screen).