Condition in controller select the next id

I try to select an ID in my controller and add +1 to select the next one but it's return my a null object . someone have an idea how to select +1 id ? thanks a lot in advance

here my controller

//condition if checkbox is selected !

        if($licencie_amateur->surclasser === true ){


            $licencie_amateur->lb_surclassement =  ActiviteLicencie::where('catg_licence_id' ,  '=' , $categorie_age->id+1 )->first();

        }elseif ($licencie_amateur->surclasser === false){

            // do nothing 

        }

via Mathieu Mourareau