Operador coalescing:
$username = $task->user->name ?? 'no existe';
Operador null_safe:
$username = $task?->user?->name? ;
Mediante optional:
$username = optional($task->user)->name;
Request form:
public function user(): BelongsTo
{
return $this->belongsTo(User::class)->withDefault(
['name' => 'Sin usuario']
);
}