Navigate to Integrations > Instant.
Select "New Action +"
Add the URL of the webpage of the button or link
Add the action element's CSS selector (see below)
Hit save and you're done!
How to find CSS selector
right-click on the element and select
inspect, hover over the HTML tags and find your desired element (it will be highlighted) in the source pane then
(right-click) > Copy > Copy selector.