Custom Pivot Column not appear when attach

Tables\Actions\AttachAction::make()
                    ->form(fn (AttachAction $action): array => [
                        $action->getRecordSelect(),
                        Forms\Components\Select::make('language')
                            ->options([
                                'KH' => 'Khmer',
                                'EN' => 'English',
                                'FR' => 'French',
                    ])
                            ->required(),
                    ]),

Tables\Actions\AttachAction::make()
                    ->form(fn (AttachAction $action): array => [
                        $action->getRecordSelect(),
                        Forms\Components\Select::make('language')
                            ->options([
                                'KH' => 'Khmer',
                                'EN' => 'English',
                                'FR' => 'French',
                    ])
                            ->required(),
                    ]),