OnePlus 9R gets OxygenOS 12 Open Beta 1: What’s new and how to install

The OnePlus 9R that was launched in 2021 was left behind when the OnePlus 9 and 9 Pro were updated to OxygenOS 12 based on Android 12. Now, the 9-series budget-flagship finally gets its first taste of OxygenOS 12 thanks to an open beta build that the brand just released.
As per a post on the OnePlus community forums that you can find here, the new build comes with a number of changes to the interface, also bumping up the version to Android 12 and adding the February Android security patch.
The changes also included multi-level dark mode settings. A new OnePlus Shelf, Canvas AOD 2.0 and many more additions. A full changelog is available on the forum mentioned above.

However, do note that this is a beta build and that you may run into a few bugs until the stable update comes out. If you are an early adopter who wants to proceed, here’s how to install the open beta build easily.
OnePlus 9R OxygenOS 12 open beta 1: How to install
First download the beta build via the link in the forums. The file is about 3.79GB in size and may take a while to completely download. Once you have it, use the stock file manager app (or any other file manager) to locate the file in your downloads folder.
You will notice that the file name ends with ‘.zip.jar’ and you need to remove the ‘.jar’ for the file to be converted into a zip file. Once this is done, simply move it to the main internal storage directory. This is your Internal Storage section, where folders like Downloads, Music, Pictures, etc ex.

Once the file has been renamed and placed in the internal storage, head over to Settings/ System/ System Updates and click on the three-dot menu on the top-right and choose Local Upgrade. A window should open up showing the file you recently placed in the root. Select it and wait for the phone to install it and restart when prompted.
Instructions to roll back to the stable Android 11 build are also given on the forum page if you want to switch back.