Adding firewall rule doesn't work

I am not sure, if this is my bad or not but I tried to add a rule to open port 3306, so I can remotely connect to mySQL
I checked the port - it is still blocked.

What amI missing?
(Using digital Ocean) and checked the port using

Hi, I didn’t know that some port are not allowed (is there a list of allow port)
Also, if you want to programmatic access the database (open connection)
how do you do that?
I thought that the way to do it is to open port 3306, is there any other way?

Yap, it seems you were right!

I am using digitalOcean
and I had to change the mysql cnf file from 127.0.0.1 to 0.0.0.0
also I added a rule in the firewall of cyberpanel to open the port 3306 only to my IP (and to all)
and I think the connection was success, also I think the cyberpanel security rule protect me a bit from the general opening of 3306 to all ip’s.
Thank you.

(And also had to open a new user in the database)