Getting the PowerApp ID
Before we start making any changes to SharePoint, there are some basic details that we need to find out about our app. For SharePoint to use our PowerApp, we need to provide either the Web Link or the App ID for our app. This is a shortcoming of the user experience for adding our app to SharePoint at this time, and I fully expect this to be improved in the future.
To get the details we need, return to the main apps list by selecting PowerApps from the app launcher in the top-left corner of the screen. If your app appears on the home page, then you can perform the following actions from there; otherwise, click Apps on the left-hand menu and locate your app.
Once you have located your app, select the ellipsis (...) to the right of the app name, which will expand out the app menu, exactly the same as when we were accessing the version history. From there, click on Details, which can be found at the bottom.
The Details screen displays some key pieces of information; the most important for this task is to capture the Web link or the App ID. Either of these details can be used, so either copy one of the identifiers to the clipboard or paste it into Notepad if you want to be sure that you're not going to accidentally clear it:
Now that we have this information, we can go to SharePoint and surface our app on a page.