Item Command Converter
In 1.20.5, Mojang has moved from unstructured NBT to the so-called item components. While Minecraft will automatically update all existing items for you, only Paper will update commands and text components containing items where possible. This tool helps you convert old item commands to the new format externally.
Note that you need to select the Entity Argument mode if you want to convert entity data outside of the summon command, as we require the entity type to convert data correctly.