How do I check if a specific element on a website is changed?

I am currently trying to get a spot in a zoom class, and if I don't get a spot I owe a driving school 300 dollars. Long story there, but not very important. I am trying to get a notification if the zoom registration link data has been updated. I originally tried to just see if the hash of the site was updated at any point, but I noticed there must be some internal clock that is changed, making it notify me every minute. The specific element I am looking to see if it is removed is...

<div class="form-group registration-over">Registration is closed.</div>

I am not sure how to isolate it within the hash. Below is the code I have for checking for any update.

import time
import hashlib
from urllib.request import urlopen, Request
import webbrowser
 
url = Request('URL HERE',
              headers={'User-Agent': 'Mozilla/5.0'})

response = urlopen(url).read()
 
currentHash = hashlib.sha224(response).hexdigest()
print("running")
time.sleep(10)
while True:
    try:
        response = urlopen(url).read()
         
        currentHash = hashlib.sha224(response).hexdigest()
         
        time.sleep(30)
         
        response = urlopen(url).read()
         
        newHash = hashlib.sha224(response).hexdigest()
 
        if newHash == currentHash:
            continue
 
        else:
            from datetime import datetime
            now = datetime.now()
            nowtime = now.strftime("%H:%M:%S: ")
            print(nowtime, "Something changed")
            webbrowser.open('URL HERE')
 
            response = urlopen(url).read()
 
            currentHash = hashlib.sha224(response).hexdigest()
 
            time.sleep(30)
            continue
             
    except Exception as e:
        print("error")