@psix.anp
Ok, found it.
It was for different device, but with Xiaomi the idea is the same.
1.Put the hub into paring mode
2. Long press a button on device until is starts blinking
3. Release the button, wait for device to stop nlinking
4. Short press button with the same time interval to prevent device going into sleeping mode
Note the led, press button only if the led is off