If no update appears, you can check for "Tryout versions" by tapping the three dots in the top right corner. Manual Firmware Flashing
If an update is available, follow the onscreen instructions to download and install it. Via My HONOR App Quick Services and select Firmware HONOR 90
The safest way to update your firmware is through the device settings or the official Via Settings and select System & updates Software update If no update appears, you can check for