Custom button “Go Ahead”

Hello,
First, thanks you for your plugin it’s the most easy chained quiz plugin and i use it on a lot of website !
Here my problem, i want to add an icon ( a cloud, link : https://www.w3schools.com/icons/tryit.asp?filename=tryicons_fa-cloud ) instead of the go ahead button it is possible to just add the icon or add the link of the library button in the plugin? Thanks you.

The page I need help with: [log in to see the link]