Well you can use HCFR which is free, but your better off imho using Chromapure or Calman 5. All options will require you have a meter though.
The one software that imho is a must when working with panasonics is ControlCal. Lets you control the display from your laptop and save the settings files as well as load others settings files. Ex. I can give you my controlcal xml file and you can load it up and send it to your display in a mater of seconds.
Also its great for copying settings to other inputs as well.
LivingRoom: LG OLED65E6P / Oppo UDP-203 / Anthem MRX 1120 / SVS SB12 / M5300-PM / Def Tech BP-8060ST, Mythos Ones x 2, Eight, Gem XL x2 / PS4 Pro / Xbox One S / Wii U
Bedroom: Panasonic 65ZT60 / Oppo BDP103D / Apple TV / PS3
Office: Pioneer KRP-500M / Xbox 360
CalMan Enthusiast, ChromaPure, HCFR, i1D3 Pro, i1Pro, SpectraCal C6, MobileForge, Lightspace, Umik1