Create database.db and Database.php

assets/models/Database.php

+<?php
+
+abstract class Database
+{
+  protected PDO $pdo;
+
+  public function __construct()
+  {
+    $this->pdo = new PDO('sqlite' . dirname(__FILE__) . '/database.db');
+    $this->pdo->setAttribute(PDO::ATTR_DEFAULT_FETCH_MODE, PDO::FETCH_ASSOC);
+    $this->pdo->setAttribute(PDO::ATTR_ERRMODE, PDO::ERRMODE_EXCEPTION);
+  }
+}