I found these instructions on the internet:

1. open the Bluetooth settings of your device and delete / "forget" your Smart Body Analyzer.
from the list of saved Bluetooth devices. 2.
Remove one of the batteries for ten seconds. 3.
3. insert the battery again. 4.
4. as soon as the word "Hello" appears on the screen of your scale, press and hold
press and hold the two buttons
buttons on the back of the scale for 20 seconds until the word "Factory" appears.

You will certainly find the instructions for your scale in the user manual under the item

... Reset to factory settings