How to use refresh token with UserInfo and Sheets API

[tenbasetom]

Currently my Chrome extension uses identity.getAuthToken() to handle authorization before calling GAPI. This works fine in Google Chrome, but my problems started when I tried to add support for Edge and Firefox, which do not support identity.getAuthToken() -- I have to rely on identity.launchWebAuthFlow() instead. My problem is that identity.launchWebAuthFlow() returns only the access token, which expires too quickly. This results in a bad UX because the user has to reauthenticate too frequently. Is there a way to use a refresh token instead?