Fitness tracker counts only steps?

I bought the huawei band a1 and actually it is the internet that counts the calories consumed but it only counts the steps and how much I used it, but when I'm lying or sitting I use something besides the basal metabolic rate or not?

And not even these details are exactly what you have consumed while running.

Was not my question

I just wanted to tell you that the whole fitness bracelets show no exact values.