CheckboxList for pivot table values loading state from DB.

 CheckboxList::make('contact_type')
                            ->options([
                                'is_A' => 'A Value',
                                'is_B' => 'B Value',
                                'is_C' => 'C Value',
                                'is_D' => 'D Value',
                            ])
//trying the below without success.
                            ->relationship('locations')
                            ->pivotData([
                                'is_a' => true,
                            ])