Python で OctoPrint で Marlin でステッピングモーター開放

#!/usr/bin/env python3

import urllib.request
import json

url = 'http://octoprint:5000/api/printer/command'
json_data = json.dumps(
    {
        'command': 'M18 X Y Z',
    }
).encode("utf-8")

with open('api-key') as f:
    api_key = f.read().rstrip()

req = urllib.request.Request(url)
req.add_header('X-Api-Key', api_key)
req.add_header('Content-Type', 'application/json')
req.data = json_data

with urllib.request.urlopen(req) as f:
    print(f.read().decode())