If you have an ASUS ROG Phone II, you can sign up for the ASUS beta program to experience Android 11 before everyone else. The ROG Phone II was released in 2019 with Android 9 Pie, received an update to Android 10 last year, and is expected to get Android 11 soon. With the ROG Phone II, the company also beta tested the Android 10 update before rolling it out to the masses, and it did have a handful of bugs, though that's obviously to be expected. Just like back then, ASUS says that the Android 11 beta program is not for someone who is "expecting a trouble free experience".

ASUS has opened up a signup link to participate in the beta program and has also confirmed a number of details about it. Taking part in the beta program will not void your warranty, and you will be able to leave the beta program at any time. The ASUS beta program is entirely confidential, and a new, private board will be created on the official ASUS forum for users who are participating. You can submit bug reports and ask questions in that forum.

ASUS ROG Phone II Forums

The most recent update for the ASUS ROG Phone II brought its security patch level to August 2021, so while the phone is still getting updates, you'll have to wait a bit to get Android 11 officially.

If you don't want to wait for ASUS to roll out Android 11, you can install an Android 11 custom ROM from our forums. OmniROM is one of the most popular, community-built third-party ROMs for Android devices and its latest version — OmniROM 11 — is based on Android 11. XDA Senior Member micky387 had been maintaining OmniROM for this device for a while, and now there's an official build of OmniROM too. Other ROMs you can try include Evolution X and BlissROM.