Follow the below steps to use Facebook wave feature
Step 1. Type www.facebook.com in the browser.
Step 2. Type your username and password to login the Facebook.
Step 3. Type the name of the person you want to message in the search box.
Step 4. Check if that person is your friend on Facebook.
Step 5. If not, send him/her a friend request. You cannot wave to someone on Facebook who’s not on your friend list.
Step 6. Check if your friend is active on Facebook chat messenger. Look for a green dot.
Step 7. You will see a hand appearing if you move the cursor near the green dot.
Step 8. Just click on it. And you can wave at your friend.
Step 9. You can also see when your friend waves back at you.