curl --request PATCH \
  --url https://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid} \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "billing_anchor_day": null
}
'

import requests

url = "https://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid}"

payload = { "billing_anchor_day": None }
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({billing_anchor_day: null})
};

fetch('https://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid}', 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://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid}",
  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([
    'billing_anchor_day' => null
  ]),
  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://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid}"

	payload := strings.NewReader("{\n  \"billing_anchor_day\": null\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://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid}")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"billing_anchor_day\": null\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://apigw.ipxo.com/ecommerce/public/{user_id}/subscriptions/{subscription_uuid}")

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  \"billing_anchor_day\": null\n}"

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

{
  "data": {
    "uuid": "19c246a2-0ab5-3d16-9195-00d5c451ed24",
    "name": "Aut officiis eaque modi.",
    "short_description": "Magnam officiis accusantium non rerum sequi qui.",
    "status": "draft",
    "current_period_start": "2026-03-03T14:05:32.0000000+00:00",
    "current_period_end": "2026-04-03T14:05:32.0000000+00:00",
    "previous_period_start": "2026-03-03T14:05:32.0000000+00:00",
    "previous_period_end": "2026-02-03T14:05:32.0000000+00:00",
    "started_at": "2026-03-03T14:05:32.0000000+00:00",
    "terminated_at": "2026-03-03T14:05:32.0000000+00:00",
    "billing_anchor_day": 20,
    "customer": {
      "uuid": "a13651d6-148c-4b8d-acd4-06918d21856d",
      "auth_id": "a6e0382a-b841-3c2f-be5a-650ec179b4ba",
      "name": "Jaron Anderson",
      "business_entity_id": "a13651d6-13c7-4372-9279-a5f3d4035e2e",
      "currency": "USD"
    },
    "total": {
      "currency": "USD",
      "amount": "0.00",
      "amount_minor": 0
    },
    "sub_total": {
      "currency": "USD",
      "amount": "0.00",
      "amount_minor": 0
    },
    "discount_total": {
      "currency": "USD",
      "amount": "0.00",
      "amount_minor": 0
    },
    "current_phase": {
      "uuid": "a8d49ae8-52eb-3c2c-ad19-722116e39043",
      "name": "Cumque id voluptas.",
      "short_description": "Sit tempore autem et voluptas.",
      "start_at": "2026-03-03T14:05:32.0000000+00:00",
      "occurrence": "month",
      "period": 1,
      "end_at": "2027-03-03T14:05:32.0000000+00:00",
      "status": "pending",
      "created_at": "2026-03-03T14:05:32.0000000+00:00"
    },
    "has_immediate_termination": true,
    "is_in_grace_period": false,
    "expires_at": "2026-04-03T14:05:32.0000000+00:00"
  }
}