I have an issue similar to
Use a different spreadsheet.
where I want to use a different spreadsheet with the same app. It looks like my only alternative is to copy the app, and copy/paste the data in the different spreadsheet to the new copy. The problem is that I have more than data in that spreadsheet: I have scripts, buttons, named ranges, etc. Is there an easy way to copy everything over to that spreadsheet?
I can’t think of a better solution. You can’t change the sheet that’s linked to an existing app.
You could move all your data and scripts into the existing app and avoid the copy, unless you are trying to keep it in a good state while migrating to a new sheet. Then the copy is the better option.
I know you can copy entire sheet tabs to different spreadsheets, which might help make it easier, but if you are expecting to match or replace an existing sheet, I don’t know if Glide will recognize it as a matching tab in the app, even though it may have the same sheet tab name. It might see the copied sheet as a new sheet.
I think a lot how glide works is how it’s deeply intertwined in the sheet. I assume a lot of that is linked by a cryptic unique ID instead of name, so you can rename stuff and move it around without breaking the app.