Testing FastAPI authenticated endpoints with pytest

How can i use pytest for testing authenticated enpoints in FastAPI? I tried this way but doesnt work:

def test_post_create_game_with_existing_name():
login = {
    "username": "Admin_1", 
    "password": "Admin123",
    }
token = client.post("/token/", data=login)

data = {
    "game_name": "Game_0",
    "player_name": "Player_0",
    "password": "Player123"
    }
response = client.post("/game/",
    headers=token, 
    data=data)
assert response.status_code == 403
assert response.json() == {'detail': 'Game name already exist'}