Here Is How To Add Guests To An Event Who Will Not Be Attending:
Step 1: Navigate to the specific event and switch to the "Guest Manager" tab. Click on the "+" icon in the bottom left corner.
Step 2: You will be redirected to the main event page. Click on "I'm not attending"(1) and a short registration form(2) will appear. Add the non attending guest's name and email and hit "Proceed".
The process is done and the Non attending guest will now appear on the "Guest manager" tab on the admin side.
Tip: Refresh the page before repeating the process for another guest.