How to send Calendar invite links in email(Gmail)?
On your computer, open Google Calendar.
Open an event to edit.
Click Edit event.
On the right, find the "Guests" section.
Start typing the name of the person and choose someone from your contacts or type an email address to invite people who aren't in your contacts list.
To mark a guest as optional: Next to the guest's name, click the person's icon People. If you don't see the icon, hover over the guest's name.
When you're done editing your event, click Save.


You can invite people who don't use Google Calendar to your event. Just follow the steps above and invite the person using their email address.

Your guests will receive an email invitation. They can let you know if they are going by clicking the Yes, No, or Maybe links in the email.