Hey Guys.
I developted event booking app using FF and it itegrates into Google Calendar API.
I developed custom function with google_sign_in and firebase_auth functions.
As you know there are two ways to connect Google Calendar API:
- Service Account
- Google OAuth token

If all the users are allowed to connect only one Google Calendar(Admins), Service Account is the best option I think.
But if inidividual users are allowed to connect their own Google Calendar, we should use Google OAuth token as bearer token of Google Calendar API.

I tested but there are several problems:

- According to the google_sign_in package I got access token and used it to add event but it worked only one time.
After logging out and logging in again, the same access token was created and error comes like insufficient permission.
- Access token is expired after a few minutes, so we should sign in every time to add event to google calendar.
I think it should be solved and if user wants to add event, he can easily get new access token and do the best.

Please help me.
If anybody provide Flutter project which is working well, then I will refrence it.

I am totally agree with Pic - Pok .
Firebase, Flutter, Dart and Google Service APIs are all controlled by Google.
I am not sure if it is so difficult to implement such a simple functionality.

Flutter team don't think this case? => This is a really simple feature.
I am very disappointed in them.

Thanks and best regards.