How to populate multi select list with default selected values

Forms\Components\Select::make('platforms')
    ->options(function () {
        return Platform::query()
            ->get()
            ->mapWithKeys(fn ($platform) => [$platform->id => $platform->name]);
    })
    ->label(__('Platforms'))
    ->default(function () {
        return ChannelPlatformFrequency::query()
        ->where('channel_id', request()->route('record'))
        ->get()
        ->mapWithKeys(fn ($channelPlatformFrequency) => [$channelPlatformFrequency->platform_id => $channelPlatformFrequency->platform->name]);
    })
    ->multiple()
    ->required(),