Troubleshoot Flow authentication errors
In many cases, flows fail because of an authentication error. If you have this type of error, the error message contains "Unauthorized," or an error code of 401 or 403 appears. You can usually fix an authentication error by updating the connection:
At the top of the web portal, click or tap the gear icon to open the Settings menu, and then click or tap Connections.
Scroll to the connection for which you saw the Unauthorized error message.
Next to the connection, click or tap the Verify password link in the message about the connection not being authenticated.
Verify your credentials by following the instructions that appear, return to your flow-run failure, and then click or tap Resubmit.
For more help, see Troubleshooting a flow.