Well that script they tell you to include in your header or footer.
You could copy that and try your luck inside of your app settings and paste it into the script/meta tags inside header or click on the page you want it on, scroll to the bottom of the settings to edit, and input it there on the page header html.
Maybe even the html element. Have you tried either of these?
Pasting it in an HTML element didn’t work. I did paste it in the header from the settings tab, but I’m just not sure how to run it. Check this example—they have ‘Book Now’ button that runs the script and opens a popup.
I guess my question is how can I run the script to open up the intended popup? I clearly have minimal JS knowledge. I really appreciate your input so far.
Like the instructions say, the script goes in your header. You fire it via other techniques as surely explained in the documentation you’re looking at (in/around/related to the screenshot you shared). Read the docs.