How to enable PhP using FileZilla

Im new to this area, in self-study progress to finish my website. The problem I have at the moment is that i have uploaded the PHP file on the website, however, seems like my web server haven't allow PHP. Therefore my PHP code is not implemented and become comment like this:

<!--?php
    $connection = mysql_connect("host", "username", "password");
    mysql_select_db("covid_info.global_total",$connection);
    echo $connection;
?-->