curl --request POST \
  --url https://api.kraken.com/0/private/BalanceEx \
  --header 'API-Key: <api-key>' \
  --header 'API-Sign: <api-key>' \
  --header 'Content-Type: application/json' \
  --data '
{
  "nonce": 123,
  "rebase_multiplier": "rebased"
}
'

import requests

url = "https://api.kraken.com/0/private/BalanceEx"

payload = {
    "nonce": 123,
    "rebase_multiplier": "rebased"
}
headers = {
    "API-Key": "<api-key>",
    "API-Sign": "<api-key>",
    "Content-Type": "application/json"
}

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

print(response.text)

const options = {
  method: 'POST',
  headers: {
    'API-Key': '<api-key>',
    'API-Sign': '<api-key>',
    'Content-Type': 'application/json'
  },
  body: JSON.stringify({nonce: 123, rebase_multiplier: 'rebased'})
};

fetch('https://api.kraken.com/0/private/BalanceEx', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

package main

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

func main() {

	url := "https://api.kraken.com/0/private/BalanceEx"

	payload := strings.NewReader("{\n  \"nonce\": 123,\n  \"rebase_multiplier\": \"rebased\"\n}")

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

	req.Header.Add("API-Key", "<api-key>")
	req.Header.Add("API-Sign", "<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))

}

{
  "error": [],
  "result": {
    "ZUSD": {
      "balance": 25435.21,
      "hold_trade": 8249.76
    },
    "XXBT": {
      "balance": 1.2435,
      "hold_trade": 0.8423
    }
  }
}