Find the host name and port using PSQL commands

select inet_server_addr(); gives you the ip address of the server.

This command will give you postgres port number

 \conninfo

If postgres is running on Linux server, you can also use the following command

sudo netstat -plunt |grep postgres

OR (if it comes as postmaster)

sudo netstat -plunt |grep postmaster

and you will see something similar as this

tcp        0      0 127.0.0.1:5432          0.0.0.0:*               LISTEN      140/postgres
tcp6       0      0 ::1:5432                :::*                    LISTEN      140/postgres

in this case, port number is 5432 which is also default port number

credits link

SELECT *
FROM pg_settings
WHERE name = 'port';

The default PostgreSQL port is 5432. The host that the database is operating on should have been provided by your hosting provider; I'd guess it would be the same host as the web server if one wasn't specified. Typically this would be configured as localhost, assuming your web server and database server are on the same host.