curl --request POST \
  --url https://api.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview \
  --header 'Content-Type: application/json' \
  --header 'X-Suby-Api-Key: <api-key>' \
  --data '
{
  "productId": "pro_9m2k1x8s7d6f",
  "quantity": 3,
  "effective": "auto",
  "proration": "delta"
}
'

import requests

url = "https://api.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview"

payload = {
    "productId": "pro_9m2k1x8s7d6f",
    "quantity": 3,
    "effective": "auto",
    "proration": "delta"
}
headers = {
    "X-Suby-Api-Key": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {'X-Suby-Api-Key': '<api-key>', 'Content-Type': 'application/json'},
  body: JSON.stringify({
    productId: 'pro_9m2k1x8s7d6f',
    quantity: 3,
    effective: 'auto',
    proration: 'delta'
  })
};

fetch('https://api.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview', 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.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview",
  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([
    'productId' => 'pro_9m2k1x8s7d6f',
    'quantity' => 3,
    'effective' => 'auto',
    'proration' => 'delta'
  ]),
  CURLOPT_HTTPHEADER => [
    "Content-Type: application/json",
    "X-Suby-Api-Key: <api-key>"
  ],
]);

$response = curl_exec($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.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview"

	payload := strings.NewReader("{\n  \"productId\": \"pro_9m2k1x8s7d6f\",\n  \"quantity\": 3,\n  \"effective\": \"auto\",\n  \"proration\": \"delta\"\n}")

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

	req.Header.Add("X-Suby-Api-Key", "<api-key>")
	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://api.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview")
  .header("X-Suby-Api-Key", "<api-key>")
  .header("Content-Type", "application/json")
  .body("{\n  \"productId\": \"pro_9m2k1x8s7d6f\",\n  \"quantity\": 3,\n  \"effective\": \"auto\",\n  \"proration\": \"delta\"\n}")
  .asString();

require 'uri'
require 'net/http'

url = URI("https://api.beta.suby.fi/v3/subscriptions/{id}/change-plan/preview")

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

request = Net::HTTP::Post.new(url)
request["X-Suby-Api-Key"] = '<api-key>'
request["Content-Type"] = 'application/json'
request.body = "{\n  \"productId\": \"pro_9m2k1x8s7d6f\",\n  \"quantity\": 3,\n  \"effective\": \"auto\",\n  \"proration\": \"delta\"\n}"

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

{
  "success": true,
  "data": {
    "direction": "UPGRADE",
    "timing": "immediate",
    "effectiveAt": "2023-11-07T05:31:56Z",
    "productId": "<string>",
    "quantity": 123,
    "amountDueNowCents": "<string>",
    "amountDueNowVatCents": "<string>",
    "recurringAmountCents": "<string>",
    "recurringVatCents": "<string>",
    "currency": "EUR"
  },
  "message": "<string>"
}

{
  "success": false,
  "error": "UNAUTHORIZED",
  "message": "Invalid or missing API key"
}

{
  "success": false,
  "error": "NOT_FOUND",
  "message": "Resource not found",
  "data": "<unknown>"
}

{
  "success": false,
  "error": "NOT_FOUND",
  "message": "Resource not found",
  "data": "<unknown>"
}

{
  "success": false,
  "error": "NOT_FOUND",
  "message": "Resource not found",
  "data": "<unknown>"
}