общий код

app/Models/HeadTeacher.php

@@ -4,13 +4,12 @@ namespace App\Models;
 
 use Illuminate\Database\Eloquent\Factories\HasFactory;
 use Illuminate\Database\Eloquent\Model;
-use Illuminate\Support\Facades\Validator;
 
 class HeadTeacher extends Model
 {
     use HasFactory;
 
-    protected $fillable = [
+    protected $guarded = [
         'user_id',
     ];