Help?

So could it mean the problem is with itch.io?
When I try to build and run all I get is a white screen

yes that could be

did you try to check what is the bug related of?

to do so

open your link in a browser, over canvas right button, inspect element, see where it takes you.

check for errors in console.

I found these two errors:
The key "target-densitydpi" is not supported.
Runtime.js:397
[Deprecation] GainNode.gain.value setter smoothing is deprecated and will be removed in M64, around January 2018. Please use setTargetAtTime() instead if smoothing is needed. See https://www.chromestatus.com/features/5287995770929152 for more details.
Zt @ Runtime.js:397