Do smartwatch realizes to test non-invasive blood glucose?

elementary knowledge:

measure the blood sugar after an overnight fast (not eating). A fasting blood sugar level of 99 mg/dL or lower is normal, 100 to 125 mg/dL indicates you have prediabetes, and 126 mg/dL or higher indicates you have diabetes.

test the blood glucose method:

Insert a test strip into your meter. Prick the side of your fingertip with the needle (lancet) provided with your test kit. Touch and hold the edge of the test strip to the drop of blood

how does the smartwatch test blood glucose?

Using infrared sensors to capture the blood flow signals through pulse and automatical algorithm analysis, if you ask should I believe them or the result are accurate? maybe you can try to test with veekoon VKEP01 and see what happens.