Maybe try here?
Copy home customization action model from <Windchill>\codebase\config\actions\navigation-actinModels.xml to custom-actionModels.xml, and add the customization action defined in step 1
(ref https://www.ptc.com/en/support/article/CS210123?source=search)
I decided it was easier to create my own banners and jsp behavior... (although I would be interested in adding interactive notices in my banners as well)

Guidance basically came from here : https://www.w3schools.com/howto/howto_js_alert.asp
The banner info is stored in banner.txt

Then I include a jsp file to control behavior (file in the same location as banner... begin_custom.jspf)