curl --request PATCH \
  --url https://api.hubapi.com/commerce/payment-methods/2027-03-beta/settings \
  --header 'Content-Type: application/json' \
  --data '
{
  "paymentMethodUpdates": [
    {
      "isDefaultOn": true
    }
  ]
}
'

import requests

url = "https://api.hubapi.com/commerce/payment-methods/2027-03-beta/settings"

payload = { "paymentMethodUpdates": [{ "isDefaultOn": True }] }
headers = {"Content-Type": "application/json"}

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

print(response.text)

const options = {
  method: 'PATCH',
  headers: {'Content-Type': 'application/json'},
  body: JSON.stringify({paymentMethodUpdates: [{isDefaultOn: true}]})
};

fetch('https://api.hubapi.com/commerce/payment-methods/2027-03-beta/settings', 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/commerce/payment-methods/2027-03-beta/settings",
  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([
    'paymentMethodUpdates' => [
        [
                'isDefaultOn' => true
        ]
    ]
  ]),
  CURLOPT_HTTPHEADER => [
    "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/commerce/payment-methods/2027-03-beta/settings"

	payload := strings.NewReader("{\n  \"paymentMethodUpdates\": [\n    {\n      \"isDefaultOn\": true\n    }\n  ]\n}")

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

	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/commerce/payment-methods/2027-03-beta/settings")
  .header("Content-Type", "application/json")
  .body("{\n  \"paymentMethodUpdates\": [\n    {\n      \"isDefaultOn\": true\n    }\n  ]\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.hubapi.com/commerce/payment-methods/2027-03-beta/settings")

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

request = Net::HTTP::Patch.new(url)
request["Content-Type"] = 'application/json'
request.body = "{\n  \"paymentMethodUpdates\": [\n    {\n      \"isDefaultOn\": true\n    }\n  ]\n}"

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

{
  "paymentMethodSettings": [
    {
      "activeCurrencies": "USD,CAD,EUR,MXN",
      "commercePaymentMethod": "ACH",
      "isDefaultOn": true,
      "supportedCurrencies": "USD,EUR,CAD,MXN"
    }
  ]
}

{
  "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"
  }
}