Woocommerce additional field (script code) in checkout

Hello,

I want to add a shipping destination field. The field will be dropdown with all the destinations listed. I have script code here:

<script type="text/javascript">
         var smartLocation = new SmartLocation(
             {
               target_id:  "target_id2",
               placeid_name: "sp_id2",
               placename_name: "sp_name2", 

               show_infotext: false,
               show_logo: false,
               show_city: false,
               show_address: false,
               show_opened: false,
               show_description: false,
               show_default: true,

               text_place:       "Pakiautomaat",
               text_default_item: "-- Vali Pakiautomaat --"
             }
          );
     </script>

And I am wondering if I could add this field in checkout or should I use anyother code? php?