I know, it's 2024 and I'm only NOW learning PHP #coding

[Daddy-ksgc]

Permissions related I think. The SQL account you're using for $conn doesn't have access to the g_users table.

Some important advice: having errors appear in a production environment is VERY bad. One particular type of SQL error in PHP causes the DB account name and password to appear, so I would strongly suggest you turn PHP errors off in this environment or make it no longer publicly accessible.