Laravel scout (meilisearch-driver) search on many to many relationship

Question

I have a many-to-many relationship and I would to perform a search on that relationship with laravel scout (meilisearch-driver).

My models:

Beneficiary.php

<?php

namespace App\Models;

use Laravel\Scout\Searchable;
use Illuminate\Database\Eloquent\Model;

class Beneficiary extends Model
{
  use Searchable;

  protected $table = 'beneficiaries';

  public function contacts() {
    return $this->belongsToMany('App\Models\Contact', 'beneficiary_contacts', 'beneficiary_id', 'contact_id');
  }

  protected function makeAllSearchableUsing($query) {
    return $query->with('contacts');
  }
}

Contact.php

<?php

namespace App\Models;

use Laravel\Scout\Searchable;
use Illuminate\Database\Eloquent\Model;

class Contact extends Model
{
  use Searchable;

  protected $table = 'contacts';

  public function beneficiaries() {
    return $this->belongsToMany('App\Models\Beneficiary', 'beneficiary_contacts', 'contact_id', 'beneficiary_id');
  }

  protected function makeAllSearchableUsing($query) {
    return $query->with('beneficiaries');
  }
}

I need to find "contacts" of a specific "beneficiary" by search string. I tried this in my controller:

public function getBeneficiaryContactsBySearch(Request $request, $id) {
      ...

      $contacts = Beneficiary::findOrFail($id)->contacts()->search($search)->paginate($request->per_page);
      
      ...
  }

But I get the error "Call to undefined method Illuminate\Database\Eloquent\Relations\BelongsToMany::search()".

Is there a way to do that with laravel scout ?

Thanks.