you can use the property for that.
please use the itemsadder official vscode extension to edit files, it suggests you everything, do not edit files manually.
https://itemsadder.devs.beer/plugin-usage/files-editor
the property: use_mmoitem_displayname: true
example
info:
namespace: test
items:
test_inject_mmoitem:
display_name: test inject mmoitem
resource:
generate: false
model_path: minecraft:item/diamond
material: PAPER
mmoitem:
id: THUNDER_BLESSING
type: TALISMAN
use_mmoitem_displayname: true