When riding the SB20 with the Stages Link app on a connected device, the Link app does not record ride activity. A 3rd party application is currently necessary to capture and record ride data.
The Stages Link app acts only as a display for the SB20 in supplement to your 3rd party application of choice. Use of a Stages Dash computer or other cycling computer with SB20 will also capture ride data.
Develop a ride or workout plan via Stages Link website, and connect your preferred 3rd party applications to the Link Calendar for ride recording. This article explains how to link your Zwift account so that it auto-uploads completed activities into your Stages Link calendar.