You could follow the steps below to enable auto-tracking via the Reolink App.
Applies to: RLC-523WA, RLC-81PA, RLC-823 Series (RLC-823A, RLC-823A 16X, RLC-823S1, RLC-823S2, RLC-823S1W), RLC-830A, E1 Outdoor Series (E1 Outdoor, E1 Outdoor PoE, E1 Outdoor Pro, E1 Outdoor S, E1 Outdoor CX), E1 Pro (hardware version IPC_566) and E1 Zoom (hardware version IPC_566), Reolink TrackMix Series (TrackMix, TrackMix LTE, TrackMix WiFi, TrackMix PoE, TrackMix LTE Plus, TrackMix Wired LTE), Argus Track
Log in to your camera and go to Device Settings > Detection Alarm. Turn on Auto Tracking and choose a Tracking Type.
Note: Auto tracking settings are only available on Android app 4.25.3.3 or later version and iOS app 4.25.4 or later version.