If you haven't moved your data or selected a new account email address to associate with your data, you'll see a temporary email address when you sign in to a conflicting Google Account with Google Ads on it. You can change this by associating your Google Ads account with either your organisational email address or a personal email address.
Despite seeing an @gtempaccount.com email address when signed in to Google Ads, your password and security settings haven't changed. You'll continue to be able to sign in to Google Ads using your previous email address and password.
