Xbox media remotes (the official Xbox One Media Remote and Xbox Series X|S Media Remote) do not use batteries. They connect via Bluetooth Low Energy and draw the tiny amount of power they need directly from the Xbox console itself—specifically, from the USB receiver dongle that plugs into the console's front or rear port.
Once paired (a one-time process through Settings → Devices & connections → Accessories), the remote works for navigation, media playback (Netflix, Disney+, Blu-ray, etc.), volume control, and even basic game control (A/B/X/Y, D-pad, menu buttons). There's no charging, no battery door, and no "low battery" warnings.
If your remote stops responding, re-pair it via the Accessories menu. No batteries to swap, ever.