Permanent means that the correction curve is stored in the mount and you can use it without PC connected. For this to work, you need to record this curve into the mount. This can be done manually doing a correction while looking into eyepiece (old fashioned way), or you can let a software, like PHD2, do the corrections while the mount is recording them. Once there is a curve recorded in the mount, you can enable the PPEC (PEC playback in the menu). But there is a one major problem: while a mount is playing a PEC curve back, the guiding pulses will be mostly canceled by the corrections done by mount's internal electronics.
The best way how to use PEC is with GPG RA algorithm, as it was said earlier. The PEC curve will not be stored in the mount or in the Ekos, it will be freshly recorded once the algorithm is used.