I've tested it again and it's fine. I even see downloads for it from the statistics this site contains for it.  I'm using Librewolf as my web browser. I've tested 2 other browsers  which is FireFox and Brave web browser, and they both work.

Do you have some kind of setting for your web browser or is it your reigon that is blocking the use of PixelDrain.

https://pixeldrain.com/