Python selenium. How to find an element?

Question

Python

Greetings.
On the page https://www.drtuber.com/signup

I execute the code

from selenium import webdriver
from selenium.webdriver.common.keys import Keys
driver = webdriver.Firefox()
driver.get('https://www.drtuber.com/signup')
driver.find_element_by_id('signup-username').send_keys(l)

Throws an error Unable to locate element:
although the element is present.

Answer 1

signup_username, not signup-username. Take a close look....