How do you integrate an element developed by a third party into your page?

Hi everyone,

I have what I am hoping is a pretty basic request. I would like to incorporate the below calculator into our webpage. I would like to host it on WIX rather than externally. I think I need to add it to the public directory and use to build a custom element but I don’t know how to go about this. Any guidance would be much appreciated!

http://whatismycarbonfootprint. com/#about