Add another relationship in role model spatie

Question

I've another relation that attach to role but when I tried to call it in controller with with/load/relations model it doesn't work. I can't call any relationship in role model except permissions.

class Role extends \Spatie\Permission\Models\Role
{
    public static $rules = [
        'name'=>'required'
    ];
    //protected $relations = ['satkers'];
    //protected $with = ['satkers'];

    //RELATIONS
    public function satkers(){
        return $this->belongsTo(MasterSatker::class, 'master_pelaksana_satker_id', 'id')->withDefault(['name'=>'']);
    }
}

How call it in controller? I've tried show it like this $role->load('satkers') and $role->satkers, it doesn't work. I got an error Call to undefined relationship [satkers] on model [Spatie\Permission\Models\Role] and null. I tried dd the $role, here is it what i got

Spatie\Permission\Models\Role {#1587 ▼
  #guarded: array:1 [▶]
  #connection: "mysql"
  #table: "roles"
  #primaryKey: "id"
  #keyType: "int"
  +incrementing: true
  #with: []
  #withCount: []
  #perPage: 15
  +exists: true
  +wasRecentlyCreated: false
  #attributes: array:6 [▶]
  #original: array:6 [▶]
  #changes: []
  #casts: []
  #classCastCache: []
  #dates: []
  #dateFormat: null
  #appends: []
  #dispatchesEvents: []
  #observables: []
  #relations: array:1 [▼ //it just show permissions
    "permissions" => Illuminate\Database\Eloquent\Collection {#1975 ▶}
  ]
  #touches: []
  +timestamps: true
  #hidden: []
  #visible: []
  #fillable: []
  -permissionClass: null
}