I have two collections products and authors with a simple many-to-many relationship. I cannot retrieve from these two collections the data entered as a pivot in the products collection as the example:

ModelProduct.php

class Product extends MongoModel {
    protected string $collection = 'products';
    public function authors()
    {
        return $this->belongsToMany(Author::class)->withPivot('role');
    }
}

ModelAuthor.php

class Author extends MongoModel {
    protected string $collection = 'authors';
    public function products()
    {
        return $this->belongsToMany(Product::class)->withPivot('role');
    }
}

JsonData Product

{
    "_id": "669eacae26a4b8ef63038f22",
    "title": "Helloworld",
    "author_ids": [{
        "id": "669eacae26a4b8ef63038f23",
        "role": "Illustrator"
    }]
}

JsonData Author

{
    "_id": "669eacae26a4b8ef63038f23",
    "firstname": "John",
    "lastname": "Doe"
    "product_ids": [
        "669eacae26a4b8ef63038f22"
    ]
}

Laravel example for pivot “role” column

foreach ($product->authors as $author) {
    dd($author->pivot->role);
}