Adding a new button in Jumbotron section in Front Page

Hi all,

I am using Illdy theme for more than two years now and currently, I had a request to add another button (see picture below). I am trying to figure it out but currently, I can’t do it. I tried to find the theme file in edit theme so I can add a

as a new button but again I failed. Can someone advise me how I can add this button (red AAA), please?