Problem Remote SQL for CyberPanel

I have installed Remote SQL for CyberPanel according to the instructions at: Remote SQL for CyberPanel - 12 - Databases - CyberPanel Community

but after I tested it connected to the root user sql, the message came out:
[root @ office ~] # mysql -u root -h xxx.xxx.xxx.xxx -p
Enter password:
ERROR 2003 (HY000): Can’t connect to MySQL server on ‘xxx.xxx.xxx.xxx’ (111 “Connection refused”)

can help me?

Follow step 1 correctly. If you can’t access remote MySQL, CyberPanel can’t make use of it.