Depends on your esc - they usually have a circuit inside that steps batt voltage down for the servos. At 3S you may be fine, depends on your esc specs. Should have tell you in manual. If you're curious and have a dvm, just measure it.

The one I'm familar with is a mamba max - if you're going to run anything over 3s, you are supposed to disable the internal bec in the MM and run an external. Stepping the voltage down from 14.8 to 6v in the internal bec generates too much heat and will cause it to fail. This is what I've done with my G2R, using a castle bec. The castle bec is adjustable via castle link - can adjust the output voltage to servos.