Save relationship with pivot attributes/columns

// Relationship defined in Model
public function tags(): MorphToMany
{
    return $this->morphToMany(Tag::class, 'taggable')
        ->wherePivot('is_approved', false);
}

// Select input in a resource form.
Select::make('tags')
    ->relationship('tags', 'name')
    ->multiple()
    ->createOptionForm([
        TextInput::make('name'),
    ])