On the Go Godot Jam 4 Discord I just saw some people having issues with how to get HTML5 exports from Godot 4 to work on itch.io, and since I just had to do this for my own game submission to the jam as well I decided to jot my steps down here (and on the Discord too) as it seems to be a bit of a pain for people.
First of all export your game using the “Web” export template
Navigate to your export folder, make sure to rename your
Zip all of it up, with all the files right within the root of the zip file
Upload to itch, make sure to check “This file will be played in the browser”
Scroll down to “Embed Options” and make sure “
SharedArrayBuffersupport” is checked