difficulty with access to mysql

Question

I am trying to connect remotely to a mysql in google cloud, but I can’t. in google I created an Ubuntu vm, last version, this is my ip,

this dripping normally:

I configured the firewall as follows:

configured in iptables:

I also set up my.cnf:

surround the Namp -St command -The localhst, the port is open:

I’ve been trying for two days an external connection, but I always have the same mistake:

internally, per ssh, connects normally, only external connection q does not work.