How to capture single optins for non-nefarious purposes, obvs

I want to be notified of every single signup, not just those who click the confirmation magic link…I use a theme that captures signups and sends it to the member database…but I only see such signups to the extent the user double confirms

What code can I use so that the signup form does two actions:

-send it to the Ghost member database, as usual
-send the email address submitted to me, via Formspree or Zapier, etc.

Can one form have two actions? Or would I need to use some sort of webhook/listeners?

If someone wants to do this on freelance basis for me, I’d be happy to pay

There is a way to achieve this easily, but remember Double-Optin is extremely useful for antispam purposes.

You will be charged for spam. You considered it carefully?

yes, I don’t intend to just add anyone, I will see what emails come in and decide…plus, single optins are fine in North America, unlike in EU under GDPR

I have been working on the form code like this:

<form data-members-form='subscribe' class='c-subscribe-form {{ formClass }}' action='https://formspree.io/f/XXXXXl'
  method='POST'>

but doesn’t work (this is from the world famous Krabi theme)