When you first try to visit phpPgAdmin after compiling/installing PostgreSQL on your server, you will see the following notice. In other words, you won't be able to use phpPgAdmin.

It appears that PostgreSQL support was not enabled for your PHP installation. To use PgSQL with PHP, you will need to recompile PHP using the -with-pgsql configure option.

This is due to the absence of a compiled version of PostgreSQL in the internal cPanel php. It is recommended to recompile cPanel's internal PHP with PostgreSQL support. The reason is that PostgreSQL was not included in the compilation of the php used by cPanel internally.

Please run the following script, or have your site host do it.

/scripts/makecpphp

A refresh may help, or you can try logging in to phpPgAdmin from cPanel.