Where's your code? Are you doing any looping (trying to load the website multiple times a second will result in an error, not sure if there's something else too as you've not added your code - feel free to dm if you don't want to post it publicly but remove login details if there are any).
time.sleep(1000) would be enough to add to a loop to stop the error - the time is in milliseconds if you want to edit it.
my code is on the <img> element i posted but i will still type them if it is not visible
! pip install BeautifulSoup
import urllib
import re
from bs4 import BeautifulSoup
import time
time.sleep(1000)
r = urllib.request.urlopen('https://bitcointalk.org/index.php?').read()
soup = BeautifulSoup(r, 'html.parser')
type(soup)
I added the time.sleep(1000) but instead the entire cell went to sleep then finally popped up with the same error message:::
HTTPError: HTTP Error 403: Forbidden