How to set Fraction value Of slider bar

i m new in blynk platform

i want to know how to set fraction value of slider in mobile app

i want only 3 steps
-1 0 1
i just want to take sllider 3 steps only

Blynk legacy or Blynk 2.0 ?

Blynk 2.0
You have to set slider value min -1 max +1 in the web dashboard

Your app slider will take its min/max from your datastream, so that has to be configured with a min of -1 and max of 1

Personally, I’d use a step slider or segmented switch in the app.