If you are running a custom ROM or have a rooted device, a simple OTA might fail. You can manually flash the OTA firmware using these methods: Using Custom Recovery Download the OTA zip file for the Official Realme Firmware Support Boot into recovery by holding Power + Volume Down Apply update from storage , navigate to your file, and flash it.
As of the current support cycle, the RMX2189 has received significant support from Realme. The device originally launched with Realme UI 1.0 (Android 10) and has since received the major Android 11 update (Realme UI 2.0) in many regions. rmx2189 ota update