You could follow the steps below to enable auto-tracking via the Reolink App.
Applies to: RLC-823A, RLC-823A 16X, RLC-523WA, E1 Outdoor, E1 Outdoor PoE, RLC-830A, Reolink TrackMix, TrackMix LTE, TrackMix LTE Plus, TrackMix WiFi, TrackMix PoE, E1 pro (hardware version IPC_566) and E1 zoom (hardware version IPC_566)
Log in to your camera and go to Device Settings > Detection Alarm. Turn on Auto Tracking and choose a Tracking Type.