Integrating Keap with Unbounce

I’m trying to integrate Keap with unbounce to collect leads through their landing pages. Unbounce asks for the Application name or URL and gives this example of how it should look:
I tried different keap url’s but nothing has worked. What is keap’s name or URL for this purpose?

Also, where do I get the API key? I’m given three options in Keap: Personal access token, Service Account Keys and Legacy Key. I tried the service account key and legacy key, but Unbounce says it’s an invalid key.

Keap support wasn’t able to help me because they say they are not trained in this.

Quick Update. Here’s what Unbounce said about this:

I touched base with my team who informed me that in this scenario, the best solution is to contact the Infusionsoft support team since their platform is what is determining the integration to be invalid. Their team will be experts and able to provide you with some more info as to why that is happening.

You could CC them to this email if you’d like so we can try our best to help however we can on this end!

Lastly, I’m also sharing this article that I hope will be helpful too > Why is my Infusionsoft API Key invalid? - FuseDesk Help Desk and Messaging Platform