Not just your fingers, but your writs, forearms, upper arms, shoulders and brain too.
You have to really want to conquer this problem and the solution lies purely with you.
Play one octave of the scale of B with your right hand (B is the best because your long fingers occupy black notes).
However slowly of quickly you play this, fingers not actually involved in playing notes will lie naturally on the keys if they are relaxed. The only thing that will cause them to rise in tension in the finger muscle.
As you go up and down the scale, mentally tune in to the muscles in your wrist, forearm, upper arm and shoulders. Allow them to relax.
Once you have learned how it feels to play without unnecessary tension, you can apply this to the rest of your playing.
Dead easy to describe. Tough as old ships' biscuits to carry out. Good luck.
Steve