import requests

s = requests.session()
username = ''
password = ''

loginPayload = {'username': username,
                'password': password,
                'autologin': 'on'}

headers = {'x-requested-with': 'XMLHttpRequest',
           'referer': 'https://www.hltv.org/'}

r = s.post('https://www.hltv.org/login', data = loginPayload, headers=headers)

if r.json()['success'] == True:
    print('logged in')
else:
    print(r.json()['errorMessage'])