You can try this Godot web player to test your game in the web with just your .PCK file and if it works, you can host the game on that website too :)
https://gotm.io/web-player
Congrats on getting your entry submitted anyway!
I've tried it and when I just uploaded the .pck file, it worked. But when I tried to release it, it didn't work. :-( Probably due to the compression.
