Quantitative recipes

I'm not sure if anyone here has asked this before but I would like the ability to, in a smithing or anvil recipe, specify a required quantity of an item. There are mods for 1.16.5 that incorporate this, and I would like the ability to do this myself. It would be cool to see this as a feature in MCreator, but if someone knows how to code this sort of thing then PLEASE let me know [I'm using the MCreator snapshot for 1.16.4]