Cant connect to any of the specified MySQL hosts

I have recently installed nopCommerce 4.3 on a remote VPS (Ubuntu/NGINX),
I created a new database in the folder "/var/lib/mysql".
I also created the appropriate user with full admin privileges.
When I go to the site the "Install" page is displayed, as expected.
In the database setup section I use the following:
Database: MySQL
Server Name: <IP Address of the server>
Database Name: <Name of the database I created>
User Name: <User name I created>
Password: <Password I created>
When I click on the Install button I get the massage: "Unable to connect to any of the specified MySQL hosts ".
I have verified that the service MySQL is running,
Where I am wrong? Any help would be greatly appreciated.

In the database setup section I use the following:
Database: MySQL
Server Name: <IP Address of the server>
Database Name: <Name of the database I created>
User Name: <User name I created>
Password: <Password I created>
When I click on the Install button I get the massage comingle: "Unable to connect to any of the specified MySQL hosts ".
I have verified that the service MySQL is running,