If you're trying to join an event and you have arrived late, you may see a Knock button when trying to enter. It looks something like this:

If you click it, you will need to wait for the host to let you into the call.

If the host denies your entry you will see a message like this and not be able to join:

If you're denied because it's too late to join, please don't be disheartened, there are many other events that you can join! We also recommend adding events to your Google calendar so you get notifications just before they're about to begin. This article shows you how!