Many to Many Problem

Hi, I am have a problem in the relationship many to many. after executing, only pivot data appears.

In Member model

    . . .
    class Member extends Authenticatable {
    
    public function interest() {
            return $this->belongsToMany(Interest::class, 'member_interest', 'member_id', 'interest_id');
     }

    . . .

I try to transform data on Resource API. and result data below

    . . . 
    "interest": [
            {
                "pivot": {
                    "member_id": 1,
                    "interest_id": 1
                }
            },
            {
                "pivot": {
                    "member_id": 1,
                    "interest_id": 2
                }
            },
            {
                "pivot": {
                    "member_id": 1,
                    "interest_id": 3
                }
            }
        ],

why data from interest tables does not appear?

thanks a lot of