Sometimes the general Wazzup chat is not displayed automatically in the left panel of Bitrix. In this case, add it manually.
1. Go to the Bitrix24 Marketplace → click "More" → Wazzup.
2. A window with Wazzup chats will open. Copy the link from your browser's address bar:

3. Go to the menu settings. To do this, select "Configure menu" → "Add link to menu" in the left panel of Bitrix24.
A window will open. Enter the name Wazzup and the chat link you copied earlier. Click "Save". Done!