So say that you have been running your TrueNAS SCALE 24.04 or 23.10 or older happily with your TrueCharts apps installed (as happy as you could be with that buggy mess of a project).
You either stuck with 23.10 Cobia, because you didn't want to bother doing yet another TrueCharts troublesome migration where they removed did something with PVC rearrangement and expected you to re-setup all your apps yet again (!), or you upgraded to 24.04 Fangtooth either while ignoring these instructions and apps still kept on working or running the PVC migration script as intended.
You kept your apps config storages to PVC as that was a simple default. (You start to grow a certain regret of not using host path mounts for everything from the beginning, but that's all water in drain now.)
Now you want to backup that data so that you can move to Docker-based apps in upcoming 24.10 Electric Eel release flawlessly and gracefully, and be happy everafter.
This tutorial and a bunch of pointers here is for you then