import requests

url = "https://platform.ankra.app/api/v1/clusters/upcloud/{cluster_id}/node-groups/{group_name}/instance-type"

payload = { "instance_type": "<string>" }
headers = {
    "Authorization": "Bearer <token>",
    "Content-Type": "application/json"
}

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

print(response.text)

{
  "group_name": "<string>",
  "updated": 123
}