refreshToken property
The Refresh token is the credential that is used to obtain a new access token when the current access token becomes invalid or expires.
Required when using refresh token flow, i.e. if grant_type
is
'refresh_token' See https://www.rfc-editor.org/rfc/rfc6749#section-1.5 and
https://www.rfc-editor.org/rfc/rfc6749#section-6
Optional.
Implementation
core.String? refreshToken;