Show/hide button in a repeater when checkbox in the item is checked.

Here is my code that does not work:

$w . onReady ( function () {

$w ( '#TeamAppdata' ). onReady (() => { 
    $w ( '#repeater1' ). onItemReady (( $item ,  itemData ) => { 

        $item ( "#checkSelect" ). onChange (( event ) => { 

        }); 
        **if**  ( $item ( '#checkSelect' ). checked ) { 
           $item ( '#btnAddToTeam' ). show (); 
        }  **else**  { 
            $item ( '#btnAddToTeam' ). hide (); 
        } 
    }); 
}); 

});