Linking 3rd party script to button

I am integrating a 3rd party div modal to a website and need to open in with a button click. I can easily do this with a text link, but am having trouble with the button. The instructions provided by Planning Center, the 3rd party, are as follows.

Here is my site Read-Only: LINK
(how to share your site Read-Only link)

Have you tried placing the button in the link block?