Laravel 5.6 spatie query builder custom filter one to many relation filter not working

I am using the Spatie/laraver-query-builder package to make some filters in my application.

I have a hasMany relation that looks like this:

ImageRequest Model:

public function requestTypes()
{
    return $this->belongsToMany('App\RequestType');
}

RequestType Model:

public function imageRequests()
{
    return $this->hasMany('App\ImageRequest');
}

I have a table image_requests and table request_types and inbetween a pivot table image_request_request_type.

request_types table

pivot table

Now I am trying to filter my image_request rows by the type field in my request_types table like this:

private $allowedFilters = [
    'id',
    'user_id',
    'pv_number',
    'begin_date_of_facts',
    'end_date_of_facts',
    'begin_hour_of_facts',
    'end_hour_of_facts',
    'location_of_facts',
    'attachment',
    'description',
    'status',
    'comment',
];

//

$query = QueryBuilder::for(ImageRequest::class)
    ->with(['requestTypes'])
    ->allowedIncludes('requestTypes')
    ->allowedFilters($this->allowedFilters, (Filter::custom('type', RequestTypeFilter::class)));

My RequestTypeFilter (based on spatie/laravel-query-builder documentation):

public function __invoke(Builder $query, $value, string $property) : Builder
{
    return $query->whereHas('requesttypes', function (Builder $query) use ($value) {
        $query->where('type', $value);
    });
}

My error message when trying to filter not even on type but on other field in image_requests table: (http://127.0.0.1:8000/?filter[pv_number]=651&filter[type]=)) when I remove the type filter it works.

(1/1) InvalidFilterQuery Given filter(s) type are not allowed. Allowed filter(s) are id, user_id, pv_number, begin_date_of_facts, end_date_of_facts, begin_hour_of_facts, end_hour_of_facts, location_of_facts, attachment, description, status, comment.

via Chebli Mohamed