Script/ program to download a pictures from website

Ok, so I have to generate about 10000 fake captchas for my bachelor degree that I must use my custom made "OCR" algorithm on later. I tried other captcha sources for captchas but I cannot store the captcha image with it's code as the image name, or at least I didn't see how. Bassicaly I test how my algorithm can test the vulnerabilities of these captchas as opposed by the google tesseract.

So I found this website www.fakecaptcha.com that lets me generate a fake captcha with the code that I type. This is the first step on the website

Then you must wait a second or two before it completes and click view my captcha

And finally I cand download the captcha to store for later use, I want to download it with the code I put earlier as the file name (code.jpg) here

So if anyone can help me with a script/program example that puts two 4-5 strings as the input then downloads the pictures with the strings as the filename, it would be greatly apreciated. How can I do it? Obviously I can't do it manually as I would go insane with that amount of pictures. Thank you in advance.