Apache 2.4 + PHP 7.2 + MariaDB 10 authentication

Upgrading client's server from CentOS 6 (Apache 2.2, PHP 5.6, mySQL 5) to CentOS 7 (Apache 2.4, PHP 7.2, MariaDB 10). Client has a membership website where you need to log in with a valid username (email address) and password. This login info is stored in mySQL database, and is referenced in .htaccess file using standard Apache mySQL authentication - and it works great - on the old CentOS 6 server. However, moving to the new CentOS 7 server, that code does not work - mySQL (MariaDB) authentication apparently is all new format and needs to be in Apache config file instead - with completely new syntax. I've tried a number of things, followed official Apache documentation, but cannot get this to work. The database is there, I can access it via phpMyAdmin, I see the logins/passwords, but the authentication code I put in Apache config files does not seem to be working. I see errors like "user abc@[login to view URL] not found" even though I clearly see user abc@[login to view URL] in the database. A small complication may be, perhaps, that passwords are stored in MD5 format in the database - not sure if that makes a difference. I basically need help getting the authentication code sorted out in Apache config - that will work on Apache 2.4, PHP 7.2 and MariaDB 10. I can provide SSH/phpMyAdmin access to the new server. I'm clearly missing something obvious, but rather than waste any more time I thought I'd hire someone for a quick project to help me with this. I'm expecting this to be a minor project, maybe an hour at the most...? It could be something as simple as a copy/paste of working code from a working server you have, for all I know. :-)