Information not showing in pop up

I just installed Spiffy Calendar so maybe I am not reading everything I need to.
See this site: https://thebuckhorninn.com/wp/
When you mouse over the date: MArch 31. Easter Buffet shows up. But how do people see the rest of the description I have put in telling phone number?

Thank you. This looks to be exactly what I need if I can figure this out.

https://www.ads-software.com/extend/plugins/spiffy-calendar/