When you click on it, a form will appear where you can enter the data:

Measurement Date (see 1)
Measurement Time (see 2)
Weight (see 3)
Height (see 4)
BMI (see 5) - the index is calculated automatically after entering the height and weight.
Bones (see 6)
Muscles (see 7)
Fat tissue (see 8)
Water content (see 9)
Notes (see 10)