Sendgrid check if email was sent

I am sending dynamic created emails from my website with sendgrid.

Everything works fine, but I want to check if an email really has been delivered. When the email is sent to sendgrid I receive the status message 202 (email was processed).

Sendgrid has a webhook feature that gives updates of delivery status of the posted email.

How can I receive the sendgrid webhook message on my wix site?
Which URL would I have to post into the sendgrid webhook post URL?

Thanks for ideas!