I was getting an error I had never seen before when uploading to itch (error listed at the bottom because its big). I am using unity version 202.3.34f1 (unsure if it just happens in this one but its the first time I've run into this problem). you need to go in Unity into Project Settings -> Player -> WebGL settings (its the symbol with the number 5 inside it) and got to the Publishing Settings drop down, for Compression Format select Disabled
Unable to parse Build/ActualCurrentBuild.framework.js.br! This can happen if build compression was enabled but web server hosting the content was misconfigured to not serve the file with HTTP Response Header "Content-Encoding: br" present. Check browser Console and Devtools Network tab to debug.