Enable the RecipeBox Share extension
First access the recipe in your app and tap the Share button. This button will be in a different location on each app.

You'll see a row of your latest text messages and a row of apps. Scroll the row of aps all the way to the right and tap "More".

Tap Edit to edit your sharable apps
Scroll to "RecipeBox" and tap the green plus (+)
Drag RecipeBox toward the top of your apps list
Tap "Done" to finish adding RecipeBox to your sharable apps list
RecipeBox will now appear in your apps list. Tap the RecipeBox icon after sharing any recipe to save the recipe in RecipeBox.