DB connection error

Salam brother/sister,
I have recently downloaded your plugin for our local masjid: http://anatoliacentre.ca
When I activate your plugin I get the following error:

Fatal error: Class ‘DatabaseConnection’ not found in D:\Websites\anatoliacentre\wp-content\plugins\daily-prayer-time-for-mosques\Models\DailyTimeTable.php on line 171

Please advise,
I tried adding this line to db.php but it didn’t work

<?php
require_once( ABSPATH . ‘wp-config.php’ ); <—
require_once( ABSPATH . ‘wp-admin/includes/upgrade.php’ );