Call to undefined method BelongsToThrough::associate()

Select::make('country_id')
    ->label(__('country_name'))
    ->relationship('country', 'name')
    ->options(Country::all()->pluck('name', 'id')->toArray())
    ->reactive()
    ->rules('required')
    ->afterStateUpdated(fn (callable $set) => $set('zone_id', null)),

Select::make('zone_id')
    ->label(__('zone_name'))
    ->relationship('zone', 'name')
    ->options(function (callable $get) {
        $country = Country::find($get('country_id'));
        if (!$country) {
            return [];
        }
        return $country->zones->pluck('name', 'id');
    })
    ->rules('required'),

 TextInput::make('name')
        ->label(__('city.name'))
        ->rules('required|min:3|max:255')
        ->placeholder(__('city.name'))
        ->columnSpanFull(),