Fan Page Robot allows you to auto post to Google+. But if you got the error "The Google Plus username you entered is not authorized to manage this page" when posting, please read this article.
Go to Google My Business or Brand Accounts. Follow this instruction (or this instruction if you don't have Google My Business) to make sure that the email/username you were using is the owner.
If you were using the right user account but still got the error, please try the following steps to ensure that your Google account allows new apps to access the account.
- completely sign out of Google (or open an incognito/private mode on your browser). Signing out of Google may be easier for some users and below is the steps:
- Go to your Google Account page.
- Click your profile photo or email address at the top right of the page.
- Click Sign out from the drop-down menu.
- login to Google with the Google+ page owner/manager's username/password
- Visit https://accounts.google.com/UnlockCaptcha and click on Continue
- Go to Fan Page Robot, try to publish a post to Google+ again.
Thanks for your patience.