Hi sorry for english , i try to change a developer code on a site write in lumen , im new of laravel .

This is the code :

 if (!isset($_SESSION['perpage'])) {
        $_SESSION['perpage'] = 500;
    }

    if ($request->has('limit')) {
        $_SESSION['perpage'] = $request->get('limit');
    }

    if($_SESSION['user_permissions']==1){
		
      $query = $newsletters = Newsletter::orderBy('id', 'DESC')
        ->with(['app', 'category'])
        ->whereHas('app', function ($query) {
            $query->where('user_id', '=', $_SESSION['user_id']);
        });
    }

    
    if($_SESSION['user_permissions']==7){
     
     
     $query = $newsletters = Newsletter::orderBy('id', 'DESC')
        ->with(['app', 'category','user'])
        ->whereHas('app', function ($query) {
            $query->where('user_id', '=', $_SESSION['user_id']);
        });

         /*  MY CODE
         *
        $query = $newsletters = Newsletter::orderBy('id', 'DESC')
                                ->join ('apps' ,'apps.id' ,'=' ,'newsletters.app_id' )
                                ->join ('categorys' ,'categorys.id' ,'=' ,'newsletters.category_id' )
                                ->join ('users' ,'apps.id_user' ,'=' ,'users.id' )
                                ->where ('users.permissions' ,'=', 7)
                                ;    */


    }      

    
     

    if ($request->has('query') && !empty($request->get('query'))) {
        $query = $query->where('subject', 'LIKE', '%'.$request->get('query').'%');
    }

    $perpage = $_SESSION['perpage'];
    $totalcount = 1000;//query->count();
    $totalpages = ceil($totalcount / $perpage);
    $page = $request->has('page') ? $request->get('page') : 1;

    if ($page > $totalpages) {
        $page = 1;
    }

    $query = $query->offset($perpage * ($page - 1))->take($perpage);
    
    $newsletters = $query->get(['id', 'shared_id', 'category_id', 'strid', 'strid_nhf', 'trkid', 'trkid_nhf', 'subject', 'payout', 'status', 'created_at', 'expires_at', 'app_id', 'start_at', 'end_at', 'type', 'budget', 'budget_given', 'closelink', 'closepixel', 'cpc_amount', 'cpc_amountc', 'cpl_amount', 'cpl_amountc', 'cpa_amount', 'cpa_amountc', 'att_amount', 'att_amountc', 'trktype', 'track_name', 'tracking', 'tracking_append', 'trackready']);

        
    //echo $sql = $query->toSql();


    
    return view('admin_newsletters_index', [
        'newsletters' => $newsletters,
        'apps' => App::orderBy('name', 'ASC')->get(),
        'request' => $request,
        'totalpages' => $totalpages,
        'page' => $page,
        'perpage' => $perpage,
    ]);

I try to edit the query with a join to get only where the user have a permission set to 7 but dont work (the query is where i write MY CODE) .