You are now only using local users. Log in as administrator and create a local account.
When you want to be able to login with your Mendix account you need the Mendix SSO module. See documentation here: https://docs.mendix.com/appstore/modules/mendix-sso
You will then have a button to sign in with your Mendix account.
Regards,
Ronald
Ah. Thank you for the feedback. I can log in to app now to test and I understand better.
I was attempting these things from Studio, your advice tells me that this needs to be done in Studio Pro, I could not see how to do this in Studio. I was able to find the demo local user manager and member accounts and log in successfully, increasing my understanding. I did not see where I needed mxadmin and I could not log in anywhere with that account, but I did see where it is configured. Much appreciated!
Dave