When you use this code, the API returns an access token and a refresh token.
When the access token expires, use the refresh token to get a new access token.
TLDR: you are storing and attempting to use the wrong thing to get a new access token.
When you use this code, the API returns an access token and a refresh token.
When the access token expires, use the refresh token to get a new access token.
TLDR: you are storing and attempting to use the wrong thing to get a new access token.