AFIK, "power ramping" means "control power as function of actual feedrate during the contouring process".
The CNC has to support that, and the machine and laser must be configured to use it.
What kind of system do you have?
That is:
CNC?
Machine?
Laser resonator?
Does the machine tool builder offer the feature?
Have you discussed it with the builder's support staff?
But, the biggest question is,
"Why do you want it, what problem are you trying to solve?"
