API how to get records belong to user

I have an admin user who can create all the listings and am using API with postman to retrieve listings that belongs to a user.

My ListingController:

  public function getListing(Request $request){

        $listings = Listing::where('user_id',$request->input('user_id'))->get();

        if($listings->isEmpty()){
            return response(['error' => 'No records found']);
        }

        return response([
            'status' => 200,
            'message' => 'success',
            'result' => [
                'data' => $listings,          
            ],
            ]);
    }

api.php:

//Route for get listing
Route::middleware(['auth:api'])->group(function () {
    Route::get('/listing/get','API\ListingController@getListing');
});

While in postman, I added an authorize token from passport and added a user_id in the body - form-data - key section and hit send but it always return with no records found

The issue I am guessing if it could not receive the user id input but how come it does not work?