ScriptError: Authorisation is required to perform that action

Reason

You use a company email account, you need to use a personal email or ask admin to allow execution addons You used multiple Google accounts in the same Chrome session

Solution #1

  1. Use Personal Email

Solution #2

  1. Create a new Chrome profile
  2. Create a new spreadsheet
  3. Try a GPT function again

Solution #3

  • Clean up cookies in your browser
  • Login again in Google account
  • Uninstall and Install again the add-on

Solution #4

  • Ask admin of the workspace account to allow execution add-ons

Other possible issues could be found here: Troubleshooting