I dropped my SendGrid API in the Opt In Form for SP Page Builder. In the front end I get "Your subscription to our list has been confirmed. Thank you for subscribing!" but no emails are added to the sendgrid contact list.
Your Add On references, "Here is video tutorial": https://www.youtube.com/watch?v=ShOQxpX7Dcw Click through and you'll see: Video unavailable
Does your Opt-in Form actually work with SendGrid or is this just another advertising feature that doesn't work?