For internal use or for those programming around the Gmail API.
Returns a token pre-processed with httr::config(). Most users
do not need to handle tokens "by hand" or, even if they need some
control, gm_auth() is what they need. If there is no current
token, gm_auth() is called to either load from cache or
initiate OAuth2.0 flow.
If auth has been deactivated via gm_deauth(), gm_token()
returns NULL.
Value
A request object (an S3 class provided by httr).
See also
Other low-level API functions:
gm_has_token()