restore composer.json, add mysqli extension

app/Models/Billing.php

@@ -0,0 +1,34 @@
+<?php
+
+namespace App\Models;
+
+use App\Traits\LogOptionsTrait;
+use Illuminate\Database\Eloquent\Model;
+use Spatie\Activitylog\Traits\LogsActivity;
+
+class Billing extends Model
+{
+    use LogsActivity, LogOptionsTrait;
+
+    protected $guarded = ['id'];
+
+    protected $casts = [
+        'order_id' => 'integer',
+        'amount' => 'integer',
+        'transaction_id' => 'string'
+    ];
+
+    protected static $logName = 'billings';
+    protected static $recordEvents = ['deleted', 'updated'];
+    protected static $logOnlyDirty = true;
+
+    protected static $logAttributes = [
+        'order_id', 'amount', 'transaction_id', 'status', 'payment_system'
+    ];
+    protected static $submitEmptyLogs = false;
+
+    public function order()
+    {
+        return $this->belongsTo(Order::class, 'order_id', 'id');
+    }
+}