Adding a Pop-Up to a Tremont Index Landing Page

Site URL: https://magenta-tunny-l2rb.squarespace.com/config/pages

I'm designing a new page working with the Tremont template. (7.0)  It's not live yet,  but I have a screen grab below. What I'm trying to do is to add a pop-up of text to the main landing page, above the three options that lead to the sub-directory pages. (drink,eat, visit).  The pop-up would only be temporary, just to explain covid-related info.  I would want to be able to remove it later.

Is this possible? and how can I do it?

Thanks in advance!

Business plan has a pop up option, built  in. You could purchase that temporarily and go back to personal later, just don't make changes like code or other business options that changes things you would not want to lose. 

thanks!  that helped me.  this is going to be a business account eventually, so it should work out fine.