Trying to link the "BOOK NOW" button on my homepage to a pop up that I created under "Promotional Pop-Ups"

Site URL: https://www.houndhousedogclub.com

I need to get the "BOOK NOW" button on my site to link to a pop-up I created within Squarespace. I've tried a lot of different methods and cannot seem to get it to work, and this is really urgent. 

The promotional popup can't be triggered by a button click, you would need to use a plugin like this:

https://www.will-myers.com/products/p/modal-popups-in-squarespace

There are other Squarespace popup/lightbox plugins available.