This update brings compatibility to 1.21.4 (and explicitly the new item models specification).
There are new builds for the Resource (/Data) Pack Generator, but the previous version (and previously generated packs) should work fine so long as the number of custom discs in your world does not exceed 64.
That said: packs generated by this version FoxNapRPG will work for older versions of the mod as well.
Full Changelog: v0.2.1...v0.2.2