API Key

Here's the situation. I came over from to CC. I want to integrate my lead capture and other forms with my CC email list using an API key. Can anyone on planet Earth, or even in the Milky Way, explain this to me using a Constant Contact API Key?

Here's my config:

I'm running a DIVI website and using the Bloom pop up plugin to capture leads for a newsletter.

In addition, I am using Gravity Forms for my contact form.

I have contacted chat support, they ran me around in circles, then told me to email support. I emailed support days ago, and no response.

My sense is that I am running the Manhattan Project. With , you get an API key, plug it in, configure the local application, and you are done.

Any help will be appreciated.