In order to install the watch face on Android 11, you need to download an application on Google Play called Notify for Mi Band and connect the bracelet to this application. Link to it below.
Notify for Mi Band
Next, you open our application, select the watchface and to the left of the watchface you see the floppy disk icon. Click on it.
The file of the selected watchface will be downloaded to the Downloads folder, which you can find in Explorer.
You need to go to Explorer, find the Downloads folder and find the MiBand4 folder in it.
By clicking on it, you will see the folder of the downloaded watchface (there will be many numbers and letters in the name).
After opening it, you need to click on the .bin file (text) and open it with the Notify for Mi Band application. Please note that you need to click on the icon that says “Update watchface”.
After that, the Notify for Mi Band application will open and you need to click “Start update”. The watchface from our application will appear on your bracelet.