Live App Tests can be sent to production by selecting Promote to Upcoming from the Live App Testing Actions menu. New screenshots and metadata can be added or existing information can be edited before the app goes live. Note that If you want to promote the test version of an app that already has a live/published version, the APK in the test version must have a version code greater than that of the current live version. Make sure that the device that the app is being tested on is compatible with all of the features of the new version of the app. A device may be able to install the live version of an app but not the test version if updates to the app make that device incompatible.
More information on live app testing can be found in the developer documentation: