curl --request GET \
  --url https://aquila.attaxr.com/api/oob/subdomain/available \
  --cookie better-auth.session_token=

const options = {method: 'GET', headers: {cookie: 'better-auth.session_token='}};

fetch('https://aquila.attaxr.com/api/oob/subdomain/available', options)
  .then(res => res.json())
  .then(res => console.log(res))
  .catch(err => console.error(err));

import requests

url = "https://aquila.attaxr.com/api/oob/subdomain/available"

headers = {"cookie": "better-auth.session_token="}

response = requests.get(url, headers=headers)

print(response.text)

{
  "error": "<string>"
}