I’ve been looking for an easy way to do this and I am seriously gobsmacked at how ridiculously easy this was.
All I did was add a row to the Divi global custom footer, added a button with the link I wanted, then added the following CSS to the Button module Advanced Settings > CSS > main element area…
I wanted to match the look on the clients current site and this fix was absolutely perfect.
I will use this over and over!!!