4.Press “Fn + C” button into Bluetooth matching condition, the Bluetooth indicator light will flash. 5.Search “BT 3.0 Keyboard” for matching tablet to keyboard. 6.Now keyboard is matched with tablet, the Bluetooth indicator light goes out. The second time you use the keyboard:
https://www.amazon.com/Microsoft-Surface-Pro-Keyboard-Tablet/dp/B07TS5WYKW