How to Get Internal App Links
How to get in-app links?
This functionality allows you to create links to a page in your app from another page.
Just add a Source code feature to your app and click on source button.

Now click on arrow button.

Now select your feature for which you want to get in-app link.

Now click on source button.

Here is your html in-app link code.

For this example in-app link is:
<a data-offline=”true” data-params=”value_id:644″ data-state=”cms-view”>Custom Page</a>