Data in another data source

I have another data source in a Google sheet and I would like to access that data from inside another app. Is it possible to access that data in another data source without accessing that app inside of another app?

I would like to bypass the email sign-in page and have a user go to that data and maybe return without signing in.

BSS

Is your main app connected to a Sheet? You can use IMPORTRANGE to get the data from the other sheet in, but in that case it’s read-only.