If you are attempting to login to the faculty portal (Community site) as another user and are finding the ‘Log in to Experience as User’ button missing on the Contact record, review the User License of the user to determine whether it is possible to use this functionality.

Customer Community Login User License

The ‘Log in to Experience as User’ functionality is only possible to use on Contact records where the corresponding User has a Customer Community Login or Community Community Plus Login license.

Salesforce User License

You can only log into the portal for Users with a Salesforce or Salesforce Platform license by logging into their User through Setup, and then accessing the Community site through the App Launcher.