AccessType is an OAuth extension that gets sent as the "access_type" field in the URL from AuthCodeURL. See https://developers.google.com/accounts/docs/OAuth2WebServer. It may be "online" (the default) or "offline". If your application needs to refresh access tokens when the user is not present at the browser, then use offline. This will result in your application obtaining a refresh token the first time your application exchanges an authorization code for a user.
"scope": condVal(c.Scope), "redirect_uri": condVal(c.RedirectURL), "access_type": condVal(c.AccessType), "approval_prompt": condVal(c.ApprovalPrompt), }.Encode()