I’m trying to remove the first 3 characters (they are always gonna be the same) from a JSON

Example

{
  "hotelnumber" : "1234",
  "hotel_code" : "HTL2233658"
}

and I want to get this (removing the “HTL”)

{
  "hotelnumber" : "1234",
  "hotel_code" : "2233658"
}

I’d try a replace and a substring but no luck with it. Thanks in advance