If you want to block someone, just tap More on their profile and select Block user.
You have the choice between two types of blocks:
Block from chats and activities you organized: The user can no longer join activities you’re the organizer of, and they cannot contact you via private chat. However, they can still join activities you’ve joined into, which were organized by someone else.
Block from chats and all activities: The user can no longer join any activity you’re a part of, whether you’re participating or whether you’re organizing it. You will not be able to contact them via private chat, and you can’t join activities they are a part of.
To unblock someone later, go to Profile ➞ Blocked Users and tap the X on their picture.
Please use the block feature responsibly, considering that you can also mute members as a first step. Keep in mind that blocking someone also removes their access to shared meetings, so be sure it’s the right step before doing so.