I found this interesting question: How do I record the value of GET parameters passed to a Google form in hidden inputs?
One of those answers says:
Google Forms doesn't supports hidden form fields but Google Apps Script HTML Service does.
A lot of other answers refer to this one as being correct. The problem is, that page doesn't have an example of using an HTML form. I can't find any examples of using an HTML form in Google apps scripts. The answer should be in the form of a coded example, and it should show how to pass metadata in from the outside.
Just like a Google form, I want to embed this web app into my HTML game, but unlike a Google form, I want to be able to pass in metadata so I can know what version of the game people are playing when they submit the form, etc.
I've been reading the docs, looking at the reference documentation too, but they don't have any examples of doing such a thing.