I’m going by these pages which give you a complete breakdown of how to install it all:
https://www.trumba.com/help/api/spudapi.aspx
https://www.trumba.com/help/publish/embedv3.aspx
As it says on the pages, you will need to enter the first part of code into the head section in the tracking and analytics section:
https://support.wix.com/en/article/embedding-custom-code-to-your-site
Then you add the second part of the code straight into an html iframe on your page:
https://support.wix.com/en/article/adding-html-code
For the issues with browsers not displaying, read the section titled ‘When I embed my spuds in a secure page they don’t display. Why?’ from the first link.