Item not add

[GabBiswajit]

rainbow_rune: id: 2008 meta: 0 namespace: "custom:rainbow_rune" name: rainbow_rune max_stack_size: 1 add_creative_inventory: true texture: rainbow_rune
Why the item can't add in Creative Inventory?
Version 2.3.2

[justauser001]

@GabBiswajut Have You Fixed It If Yes Pls Tell me :(