Then aaPanel shows me the first alert (warning) modal when I was trying to upgrade MySQL-mariaDB 10.3 to 10.4.
First Alert to backup & delete all database to upgrade mariaDB

So, we do backup and delete all databases. Then re-starts the upgrading process. Then second alert modal come
Second alert

In fact, the second alert should come first. So, user with less than 2048 MB (2GB) RAM can refrain themself from upgrading mariaDB. It can save valuable time in deleting & restoring databases.