When you find something you want to save, look for the Share button. It can usually be found in your device’s menu, or when tapping the share menu in an app (usually found in a menu or toolbar).
When you tap Share, you’ll be presented with a list of share options, find “Whisk" to open the Whisk app, and choose to save the recipe to your Recipe Box or add the recipe to your shopping list.
See how it works in Chrome:
Tip: Pin Whisk to the Top
On some versions of Android, you can long-press the Whisk icon and select "Pin" to move the Whisk icon to the top of your Share via list.