Synchronization/updating related laravel models, how to do it normally?

Question

Laravel

There are 2 related models, how to synchronize correctly?

class Site extends Model 
{
    public function phrase()
    {
        return $this->hasOne(Phrase::class, 'site_id', 'id');
    }
}

Unsuccessful synchronization attempt:

$phrases = [];
        foreach ($request->get('phrases') as $phrase) {
            $phrases[] = (new Phrase());
        }
        $site->phrase()->sync($phrases);