How do I fix a HTTP Error 400: Bad Request in python3?

I am trying to access checkpoint firewall by using it's API but for some reason I am getting HTTP Error 400: Bad Request, I have never had this before. Any ideas? Here is my code:

import json
import ssl
import urllib.request, urllib.parse, urllib.error
import urllib.request, urllib.error, urllib.parse
import requests
from requests.packages.urllib3.exceptions import InsecureRequestWarning
requests.packages.urllib3.disable_warnings(InsecureRequestWarning)
sslctx = ssl.create_default_context()
sslctx.check_hostname = False
sslctx.verify_mode = ssl.CERT_NONE

def checkpoint_api_call(cp_ip, port, command, json_payload, sid):
    apiurl = 'https://' + cp_ip + '/web_api/' + command
    req = urllib.request.Request(apiurl)
    if sid == '':
        req.add_header('Content-Type', 'application/json')
    else:
        req.add_header('Content-Type', 'application/json')
        req.add_header('X-chkp-sid', sid)
    try:
        data1 = urllib.parse.urlencode(json_payload).encode("utf-8")
        resp = urllib.request.urlopen(req, data=data1, context=sslctx)
        res_code = resp.getcode()
        return resp_output, res_code
    except urllib.error.HTTPError as e:
        print((str(e)))
main()
    payload = {'user': admin, 'password': password}
    response, res_code = checkpoint_api_call(x.x.x.x, 443, 'login', payload, '')

source https://stackoverflow.com/questions/70489137/how-do-i-fix-a-http-error-400-bad-request-in-python3