Update the shipping order custom field with api

Update the shipping order custom field with api

Hi
I create two mandatory custom field for shipping order but I don't know how is it possible to change the value of those with API.

I add this information to JSONString but it seems that custom fields do not support for shipping order.

  1. "custom_fields": 
  2.         {
  3.             "value": "22:AD:53:34:AE",
  4.             "index": 1
  1.         },