PostgreSQl, PHP and IIS

I have PHP v7.2.7 and PostgreSQL v10 with Windows IIS.

I am trying to get this to work following any advice I have been able to
find on the web, but with no success. My configuration so far is as below.

PHP.ini extension list includes both php_pdo_pgsql.dll and php_pgsql.dll.

Both these dlls are located in the correct extensions directory according to
phpinfo.

According to phpinfo the Configuration File Path is "C:\Windows" and the
Loaded Configuration File is "C:\Program Files\PHP\v7.2\php.ini". I have the
same php.ini file at both locations.

I have copied the version of libpq.dll from the lib folder of the postgresql
installation to the root folder of the PHP installation.

I have added the bin folder of the postgresql installation to the Windows
system search path.

Phpinfo shows that pdo_pgsql extension is loaded but not pgsql.

I have also tried copying the dependent dlls (ssleay32.dll, libeay32.dll,
libintl-8.dll, libiconv-2.dll) from the postgresql bin folder to the php
root folder).

Phpinfo show php_pdo_pgsql is enabled, but not php_pgsql.dll and an
undefined function call error is displayed by php when I try and run any pg
php functions.

Can anyone please shed any light on what more I need to do?

Regards,

Mark