A fork of CITResewn for 1.21 backwards compatibility, allowing users to define nbt to component mapping rules. Has specific patches for Hypixel+.
To setup the nbt to component compatibility for packs other than Hypixel+, you will need to edit (minecraft install dir)/config/citresewn/nbttocomponents.properties, to specify global nbt rules.
Note for resource packs creators: nbt.ExtraAttributes is automagically mapped to the minecraft:custom_data component.