Change this line:

model->created_by = $user->id ? $user->id : 1 ;

Regarding:

model->created_by = $user ? $user->id : 1 ;

You must first check if$useris empty.

The problem here is that$userhas a value ofnullandnulldoes not have any attributes.

$userwill always benullwhereas your codeAuth::user()will benull. You did not have an authenticateduserduring the seeding process.

If you want to assignUserto your$modeland you have seeded theUsertable, you can get aUser like this.

$model->created_by = \App\Models\User::where('id', 5)->first();

If you don't want a specificuserthen you can do this:

$model->created_by = \App\Models\User::inRandomOrder()->first();