Final answer:
Once a username is added to the contact record in a Power Apps portal, you should set and securely communicate a password to the user, enable the contact for web access if necessary, and test the login process to ensure proper access.
Step-by-step explanation:
After adding a username to the contact record for a user to access a Power Apps portal with local authentication, you should set a password for the contact. The process involves going into the contact record, navigating to the 'Web Authentication' section, and setting a strong password that meets your organization's security policies. It may also be necessary to enable the contact for web access if this setting is not already configured.
Remember to communicate the credentials to the user securely and advise them to change their password upon first login, if your platform settings allow for it. This ensures both security for the user's account and the integrity of your Power Apps portal.
Finally, it's important to test the login process to ensure everything is working as expected, and provide the user with any necessary support during their initial access.