Many to many relation in Laravel keys?

How to set keys for relation between three tables (many to many):

distributor_contacts

distributor_contacts_instructor

distributor_instructors

Where distributor_contacts_instructor is intermediate table:

| instructor_id | distributor_contacts_id

Where distributor_contacts table is:

| user_id | 

Where distributor_instructors is:

| user_id |

I need to store in distributor_contacts_instructor value distributor_instructors.user_id to distributor_contacts_instructor.instructor_id and distributor_contacts_instructor.distributor_contacts_id to Auth::user()->id

How to set this relation in model below?

return $this->belongsToMany(DistributorContacts::class, 'distributor_contacts_instructor', 'instructor_id', 'distributor_contacts_id', 'user_id', 'user_id');

I tried, but it does not work

via Chebli Mohamed