Earlier this year, Xiaomi introduced the Mi A1 smartphone which comes with Android 7.1.2 Nougat and is part of the Android One program. The handset is expected to get Android 8.0 Oreo, and it appears the time for that is close, as the Chinese manufacturer is now looking for Mi A1 users who are willing to test the new version fo the OS. The deadline for application is 11:59 PM (Beijing Time), on December 11, 2017.
To make sure you"re eligible, you have to download the MIUI Global Forum on your device and then apply from within the app. Users are required to submit the IMEI number of their device, which will be used to send the update over-the-air (OTA). Furthermore, make sure you"re active on the MIUI forums, as you will be notified via a PM if selected.
The company also wants beta testers to install QQ on their devices, which will be used as a communication tool between the members participating in the beta program and the company. You can join the beta program regardless of your region, and the communication language is English.
Source: Xiaomi MIUI Forums via XDA-Developers