To send your link and invite your friends from WhatsApp follow these instructions:
Click on “Invite” in the bottom menu and scroll to the bottom of the page.
Click on the WhatsApp icon to open the options menu.
After that, click again on “WhatsApp” to be redirected to the application.
Once in the application select the person you want to send and that's it!, you will see in the text balloon your link and a message that you can edit.