How do I get my iOS app to contribute an action for a shortcut?

When I go to the Shortcuts app and add an action, there is a tab that lets me see Apps that has actions I can use. How do I make my iOS app be able to contribute actions for users to use in a shortcut, so that a user creating a shortcut can add an action that does something in my app?

An example of this is the Walmart app. A user can create use an action that allows him to check in.

How do I get my iOS app to contribute an action for a shortcut?
 
 
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