dotenv implementation

connection.php

@@ -1,10 +1,10 @@
 <?php
 
-$dbhost = "db";
-$dbuser = "app";
-$dbpass = "4wdcsa2025!";
-$dbname = "4wdcsa";
-$salt = "4wdcsa";
+$dbhost = $_ENV['DB_HOST'];
+$dbuser = $_ENV['DB_USER'];
+$dbpass = $_ENV['DB_PASS'];
+$dbname = $_ENV['DB_NAME'];
+$salt = $_ENV['SALT'];