Swimbot Error

Traceback (most recent call last):
  File "C:\Users\wmiller\AppData\Local\Programs\Python\Python39\lib\site-packages\discord\ext\commands\core.py", line 85, in wrapped
    ret = await coro(*args, **kwargs)
  File "c:\Users\wmiller\Desktop\Swimbot\whois.py", line 531, in seen
    last_time = datetime.datetime.strptime(last_time[:19], '%Y-%m-%dT%H:%M:%S')
TypeError: 'datetime.datetime' object is not subscriptable