ubuntu 18.04 remote root login

mysqld.cnf

To list open ports use the netstat command:
netstat -tulpn | grep LISTEN

change config:
/etc/mysql/mysql.conf.d/mysqld.cnf
bind-address            = 0.0.0.0

login mysql and run:
Grant All Privileges ON *.* to 'user'@'%' Identified By 'pass';
FLUSH PRIVILEGES;