How To Do It
To know how to poke someone, just follow these steps. Go to a friend's profile, find the poke button, and click. That's it! As simple as ABC. That person will get a notification, and then you can start chatting or interacting. Similarly, when someone does this with you, you will receive a notification as well. Just acknowledge it (or ignore it, it is your wish) and start chatting with your friend.