python requests: problem with getting a request with www.ah.nl/mijn/inloggen

Question

this is my code:

import pygame
import time
from _thread import *
import requests
pygame.init()

headers = {
    'user-agent': 'Mozilla/5.0 (X11; CrOS x86_64 12871.91.0) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/81.0.4044.127 Safari/537.36'
}

login_data = {
        'username': '13..l',
        'password': 'J..1',
    }

with requests.Session() as s:
    url = 'https://www.ah.nl/mijn/inloggen?ref=%2F/'
    r = s.get(url,headers=headers)
    b = str(r.content).split('"')
    print(s.cookies['_csrf'])
    print(b[13])

    r = s.post(url, data=login_data, headers=headers)
    print(r, r.content)

i have a project that i'm working on but in can't get it to work i need an crsftoken but i can't get it. so i get an 403 error