curl --request PATCH \
  --url https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "properties": {
    "property_checkbox": "false",
    "property_date": "1572480000000",
    "property_dropdown": "choice_b",
    "property_multiple_checkboxes": "chocolate;strawberry",
    "property_number": "17",
    "property_radio": "option_1",
    "property_string": "value"
  }
}
'

import requests

url = "https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId}"

payload = { "properties": {
        "property_checkbox": "false",
        "property_date": "1572480000000",
        "property_dropdown": "choice_b",
        "property_multiple_checkboxes": "chocolate;strawberry",
        "property_number": "17",
        "property_radio": "option_1",
        "property_string": "value"
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

response = requests.patch(url, json=payload, headers=headers)

print(response.text)

const options = {
  method: 'PATCH',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    properties: {
      property_checkbox: 'false',
      property_date: '1572480000000',
      property_dropdown: 'choice_b',
      property_multiple_checkboxes: 'chocolate;strawberry',
      property_number: '17',
      property_radio: 'option_1',
      property_string: 'value'
    }
  })
};

fetch('https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId}', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

<?php

$curl = curl_init();

curl_setopt_array($curl, [
  CURLOPT_URL => "https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId}",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "PATCH",
  CURLOPT_POSTFIELDS => json_encode([
    'properties' => [
        'property_checkbox' => 'false',
        'property_date' => '1572480000000',
        'property_dropdown' => 'choice_b',
        'property_multiple_checkboxes' => 'chocolate;strawberry',
        'property_number' => '17',
        'property_radio' => 'option_1',
        'property_string' => 'value'
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "Authorization: Bearer <token>",
    "Content-Type: application/json"
  ],
]);

$response = curl_exec($curl);
$err = curl_error($curl);

curl_close($curl);

if ($err) {
  echo "cURL Error #:" . $err;
} else {
  echo $response;
}

package main

import (
	"fmt"
	"strings"
	"net/http"
	"io"
)

func main() {

	url := "https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId}"

	payload := strings.NewReader("{\n  \"properties\": {\n    \"property_checkbox\": \"false\",\n    \"property_date\": \"1572480000000\",\n    \"property_dropdown\": \"choice_b\",\n    \"property_multiple_checkboxes\": \"chocolate;strawberry\",\n    \"property_number\": \"17\",\n    \"property_radio\": \"option_1\",\n    \"property_string\": \"value\"\n  }\n}")

	req, _ := http.NewRequest("PATCH", url, payload)

	req.Header.Add("Authorization", "Bearer <token>")
	req.Header.Add("Content-Type", "application/json")

	res, _ := http.DefaultClient.Do(req)

	defer res.Body.Close()
	body, _ := io.ReadAll(res.Body)

	fmt.Println(string(body))

}

HttpResponse<String> response = Unirest.patch("https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"properties\": {\n    \"property_checkbox\": \"false\",\n    \"property_date\": \"1572480000000\",\n    \"property_dropdown\": \"choice_b\",\n    \"property_multiple_checkboxes\": \"chocolate;strawberry\",\n    \"property_number\": \"17\",\n    \"property_radio\": \"option_1\",\n    \"property_string\": \"value\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.hubapi.com/crm/v3/objects/postal_mail/{postalMailId}")

http = Net::HTTP.new(url.host, url.port)
http.use_ssl = true

request = Net::HTTP::Patch.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"properties\": {\n    \"property_checkbox\": \"false\",\n    \"property_date\": \"1572480000000\",\n    \"property_dropdown\": \"choice_b\",\n    \"property_multiple_checkboxes\": \"chocolate;strawberry\",\n    \"property_number\": \"17\",\n    \"property_radio\": \"option_1\",\n    \"property_string\": \"value\"\n  }\n}"

response = http.request(request)
puts response.read_body

{
  "archived": false,
  "createdAt": "2019-10-30T03:30:17.883Z",
  "id": "512",
  "properties": {
    "property_checkbox": "false",
    "property_date": "1572480000000",
    "property_dropdown": "choice_b",
    "property_multiple_checkboxes": "chocolate;strawberry",
    "property_number": "17",
    "property_radio": "option_1",
    "property_string": "value"
  },
  "updatedAt": "2019-12-07T16:50:06.678Z"
}

{
  "message": "Invalid input (details will vary based on the error)",
  "correlationId": "aeb5f871-7f07-4993-9211-075dc63e7cbf",
  "category": "VALIDATION_ERROR",
  "links": {
    "knowledge-base": "https://www.hubspot.com/products/service/knowledge-base"
  }
}