If you are OTM/ATM options:
You can close the positions before 16:00 EDT of the expiration date. Be wary that it might close worthless.
For the ITM options:
You can sell the options before 16:00 EDT of the expiration date or let it automatically exercise (around 15:48 EDT) when the market is closed. If you cannot support the exercise/assignment of your option Webull reserves the right to mitigate risk by liquidating the option prior to the close at our discretion.