How can I link the built-in pop-up of the template with marketing automation?

[cicicici]

My paid template comes with a pop-up feature, and I have already set up the copy and style for the template in Shopify Email's marketing automation. However, how can I link the two together so that after filling in the email in the pop-up, Shopify Email will automatically send an email? I am very confused.
(paw-swing.com)
Andaman template

Thank you very much!