If a new Master Admin user needs to be assigned to an account, the current Master Admin must replace them from their account.
If SSO is not enabled on the account:
Due to the switch needing to be confirmed by the current Master Admin user entering their password, the account must have SSO disabled before the switch can be made.
Sign out.
Sign back in using the SSO link to verify the login.
The Master Administrator handover process is now complete.