How to add a Loading Animation when a Button is Clicked?

For my website, when a button is clicked, the screen blurs. I am now trying to add a loading animation of a spinning circle on top of that blur when the button is pressed, however, I'm running into a lot of issues. When I tried to also have the button click have "isActive" and then make the loader class div when it isActive, the entire website crashed.

js file code:

import React from "react";
import "./App.scss";

class App extends React.Component {

    state = { fadingOut: false }
    fadeOut = () => this.setState({fadingOut: true});


    render() {
        return (
            <div className="App" style={this.state.fadingOut ? {filter: 
            'blur(0.35vw)'} : undefined }
            > 

                <div className="top-bar">

                <div className="title">
                    .datapoems
                </div>

                <img className="logo" src="./logo.png"/>

                </div>

                <div className="container">
                    <div className="sloganLineOne">Poem Theme</div>
                    <div className="sloganLineTwo">Detector</div>
                    <textarea className="inputField" placeholder="Please Enter 
                     Your Poem Here..."></textarea>
                    <button className="button" onClick= 
                     {this.fadeOut}>Enter</button>
                    <img className="leftTriangle" 
                     src="./leftSideTriangle.png"/>
                    <img className="rightTriangle" 
                     src="./rightSideTriangle.png"/>
                </div>
            </div>
        );
    }
}

export default App;

scss loader code:

 .loader {
                border: 16px solid #f3f3f3;
                border-radius: 50%;
                border-top: 16px solid blue;
                border-bottom: 16px solid blue;
                width: 120px;
                height: 120px;
                -webkit-animation: spin 2s linear infinite;
                animation: spin 2s linear infinite;
              }

              @-webkit-keyframes spin {
                0% { -webkit-transform: rotate(0deg); }
                100% { -webkit-transform: rotate(360deg); }
              }

              @keyframes spin {
                0% { transform: rotate(0deg); }
                100% { transform: rotate(360deg); }
              }