Login to website using python requests

As said above, you should send values of all fields of form. Those can be find in the Web inspector of browser. This form send 2 addition hidden values:

url = "https://www.voxbeam.com//login"
data = {'userName':'xxxxxxxxx','password':'yyyyyyyyy','challenge':'zzzzzzzzz','hash':''}  
# note that in email have encoded '@' like uuuuuuu%40gmail.com      

session = requests.Session()
r = session.post(url, headers=headers, data=data)

Also, many sites have protection from a bot like hidden form fields, js, send encoded values, etc. As variants you could:

1) Use a cookies from manual login:

url = "https://www.voxbeam.com"
headers = {'user-agent': "Mozilla/5.0 (Windows NT 10.0; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/57.0.2987.98 Safari/537.36"}
cookies = {'PHPSESSID':'zzzzzzzzzzzzzzz', 'loggedIn':'yes'}

s = requests.Session()
r = s.post(url, headers=headers, cookies=cookies)

2) Use module Selenium:

from selenium import webdriver
from selenium.webdriver.common.keys import Keys

url = "https://www.voxbeam.com//login"
driver = webdriver.Firefox()
driver.get(url)

u = driver.find_element_by_name('userName')
u.send_keys('xxxxxxxxx')
p = driver.find_element_by_name('password')
p.send_keys('yyyyyyyyy')
p.send_keys(Keys.RETURN)

It's very tricky depending on how the website handles the login process but what I did was that I used Charles which is a proxy application and listened to requests that my browser sent to the website's server while I was logging in manually. Afterwards I copied the exact same header and cookie that was shown in Charles into my own python code and it worked! I assume the cookie and header are used to prevent bot logging in.

Try to specify the URL more clearly as follows :

  url=https://www.voxbeam.com//login?id=loginForm

This will setFocus on the login form so that POST method applys