Explanation
Restore a canvas app to a previous version in PowerApps.
Restore an app from your account
Open powerapps.com, and then click or tap Apps in the left navigation bar.
Near the right edge, click or tap the info icon for the app that you want to restore.
Click or tap the Versions tab, and then click or tap Restore for the version that you want to restore.
In the confirmation dialog box, click or tap Restore.
A new version is added to your list.
Reference:
https://docs.microsoft.com/en-us/powerapps/maker/canvas-apps/restore-an-app