I want to setup Event API for landing page (thank you page) visits on my website. Once my customers have booked a demo they will go to a landing page. I want mailchimp to recognise what customer landed on that page and move them to the next stage of the customer journey. What is the API code for this? And where do I put this API code on my Website. Do I put it in the body of the landing page or?

I Would really appreciate any help on this