curl --request POST \
  --url https://{defaultHost}/v1/upsells \
  --header 'Authorization: Bearer <token>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "upsell": {
    "fee_description": "Awesome Upsell",
    "step": "declined",
    "amount_off": 500,
    "price": "5bdefc77-bdb3-49d6-8c22-b491e06879a0",
    "upsell_funnel": "3765793b-0067-406c-a439-d37d01991e4b"
  }
}
'

import requests

url = "https://{defaultHost}/v1/upsells"

payload = { "upsell": {
        "fee_description": "Awesome Upsell",
        "step": "declined",
        "amount_off": 500,
        "price": "5bdefc77-bdb3-49d6-8c22-b491e06879a0",
        "upsell_funnel": "3765793b-0067-406c-a439-d37d01991e4b"
    } }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {Authorization: 'Bearer <token>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    upsell: {
      fee_description: 'Awesome Upsell',
      step: 'declined',
      amount_off: 500,
      price: '5bdefc77-bdb3-49d6-8c22-b491e06879a0',
      upsell_funnel: '3765793b-0067-406c-a439-d37d01991e4b'
    }
  })
};

fetch('https://{defaultHost}/v1/upsells', 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://{defaultHost}/v1/upsells",
  CURLOPT_RETURNTRANSFER => true,
  CURLOPT_ENCODING => "",
  CURLOPT_MAXREDIRS => 10,
  CURLOPT_TIMEOUT => 30,
  CURLOPT_HTTP_VERSION => CURL_HTTP_VERSION_1_1,
  CURLOPT_CUSTOMREQUEST => "POST",
  CURLOPT_POSTFIELDS => json_encode([
    'upsell' => [
        'fee_description' => 'Awesome Upsell',
        'step' => 'declined',
        'amount_off' => 500,
        'price' => '5bdefc77-bdb3-49d6-8c22-b491e06879a0',
        'upsell_funnel' => '3765793b-0067-406c-a439-d37d01991e4b'
    ]
  ]),
  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://{defaultHost}/v1/upsells"

	payload := strings.NewReader("{\n  \"upsell\": {\n    \"fee_description\": \"Awesome Upsell\",\n    \"step\": \"declined\",\n    \"amount_off\": 500,\n    \"price\": \"5bdefc77-bdb3-49d6-8c22-b491e06879a0\",\n    \"upsell_funnel\": \"3765793b-0067-406c-a439-d37d01991e4b\"\n  }\n}")

	req, _ := http.NewRequest("POST", 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.post("https://{defaultHost}/v1/upsells")
  .header("Authorization", "Bearer <token>")
  .header("Content-Type", "application/json")
  .body("{\n  \"upsell\": {\n    \"fee_description\": \"Awesome Upsell\",\n    \"step\": \"declined\",\n    \"amount_off\": 500,\n    \"price\": \"5bdefc77-bdb3-49d6-8c22-b491e06879a0\",\n    \"upsell_funnel\": \"3765793b-0067-406c-a439-d37d01991e4b\"\n  }\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://{defaultHost}/v1/upsells")

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

request = Net::HTTP::Post.new(url)
request["Authorization"] = 'Bearer <token>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"upsell\": {\n    \"fee_description\": \"Awesome Upsell\",\n    \"step\": \"declined\",\n    \"amount_off\": 500,\n    \"price\": \"5bdefc77-bdb3-49d6-8c22-b491e06879a0\",\n    \"upsell_funnel\": \"3765793b-0067-406c-a439-d37d01991e4b\"\n  }\n}"

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

{
  "id": "413bad95-bf7e-47a6-99ad-d021ade80e45",
  "object": "upsell",
  "amount_off": 500,
  "duplicate_purchase_behavior": "allow",
  "fee_description": "Awesome Upsell",
  "metadata": {},
  "percent_off": null,
  "replacement_behavior": "none",
  "step": "declined",
  "price": "5bdefc77-bdb3-49d6-8c22-b491e06879a0",
  "upsell_funnel": "3765793b-0067-406c-a439-d37d01991e4b",
  "discarded_at": null,
  "created_at": 1789424654,
  "updated_at": 1789424654
}