I just keep verbatim the instructions in MariaDB docs but it does not work at all, and I wast a great ammount of time.
MariaDB docs does not take into account this version in its documentation.
Following the instructions i modified the file my.cnf that in my case it was /etc/mysql/my.cnf
I comment this out as the example, but in my case I had to add it manually.
[mysqld]
...
#skip-networking
...
#bind-address = <some ip-address>
...
And as I already have an account with remote permissions, I just restarted the mysql service but nothing happened.
Check if por is open
sudo nmap -PN -p 3306 -sV server_ip
The port wasn't listening from remote ips.