Microsoft Surface Hub 2 SmCamera - Manual (Page 478)

3. If the pen is already connected to the Surface Hub, you should see Surface Hub 2
Pen listed under Mouse, keyboard, & pen.
4. If you don't see the pen listed here, select the + button to Add Bluetooth or other
device.
5. Once you see the Surface Hub 2 Pen listed in the results, you can add the pen
from here.
6. To see the battery level for your pen, navigate to All Apps > Surface > select the
Surface Hub 2S Pen.
7. Ensure your Surface Hub 2S pen firmware is up to date, as outlined here: Update
pen firmware on Surface Hub 2S