Function sqlsrv_connect() to connect to localhost phpmyadmin error

I try to connect to my localhost database in phpMyAdmin, but I get error:

Fatal error: Uncaught Error: Call to undefined function sqlsrv_connect().

How can I connect by using this code?:

$sqlConnInfo = array("database"=>DBNAME, "UID"=>DBUSER, "password"=>DBPASS);
global $sqlConn;
$sqlConn = sqlsrv_connect( DBHOST, $sqlConnInfo);