My app (not Firebase) backup data to google drive in foreground (using google_signin, and googleapis). However, backup won't run in background (as WorkManager task). The reason for this, isolates do not share memory with other threads and thus even if app is signed-in in main thread it is not in isolate. The solution I am seeking is: (1) get authorization data (access token, refresh token, expiry) during main thread and store them to SecureStorage. (2) later in background an isolate can access SecureStorage and use that authorization data.
My question is how to get and use authorization data in non-Firebase app?
