Just after install PMA cant connect

Hello folks!
After installing EE v4 on a VPS (not sure if i can say hoster name here…), i installed admin tools but phpmyadmin doesnt connect with this error: " mysqli_real_connect(): (HY000/2002): No such file or directory".
If i put “” on server field it says Connection refused.
My server is running ubuntu 16.04 LTS

Thanks in advance

Solution: i should use “global-db” for server hostname when i need to connect to mysql