curl -X POST "https://api.fitsociety.io/public/v1/workout/plans" \
  -H "Authorization: Bearer <access_token>" \
  -H "Idempotency-Key: <stable_request_key>" \
  -H "Content-Type: application/json" \
  -d '{}'

const form = new FormData();
form.append('name', '[{"lang":"en","value":"4-Day Strength Block"},{"lang":"nl","value":"4-Daags Krachtblok"}]');
form.append('description', '[{"lang":"en","value":"Progressive upper/lower split."},{"lang":"nl","value":"Progressieve upper/lower split."}]');

const options = {
  method: 'POST',
  headers: {'Idempotency-Key': '<idempotency-key>', Authorization: 'Bearer <token>'}
};

options.body = form;

fetch('https://api.fitsociety.io/public/v1/workout/plans', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://api.fitsociety.io/public/v1/workout/plans"

payload = "-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"name\"\r\n\r\n[{\"lang\":\"en\",\"value\":\"4-Day Strength Block\"},{\"lang\":\"nl\",\"value\":\"4-Daags Krachtblok\"}]\r\n-----011000010111000001101001\r\nContent-Disposition: form-data; name=\"description\"\r\n\r\n[{\"lang\":\"en\",\"value\":\"Progressive upper/lower split.\"},{\"lang\":\"nl\",\"value\":\"Progressieve upper/lower split.\"}]\r\n-----011000010111000001101001--"
headers = {
    "Idempotency-Key": "<idempotency-key>",
    "Authorization": "Bearer <token>",
    "Content-Type": "multipart/form-data; boundary=---011000010111000001101001"
}

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

print(response.text)