question

When you tokenize the card (I am assuming you are still using the tokens endpoint) you need to include the zip:

{
    "card": {
          "number": "redacted",
          "exp_month": "redacted",
          "exp_year": "redacted",
          "address_zip": 56555,
          "cvv": "123"
    }      
}

When you make the charge the response's source will contain address_zip_check:

"source": {
    ....
    "address_zip_check": "pass",
 }