how to give an advancement a background?

{ "display": { "icon": { "id": "minecraft:cherry_planks" }, "title": "More Villages", "description": "by Tomqnto", "background": "minecraft:texture/black_concrete", "show_toast": false, "announce_to_chat": false }, "criteria": { "requirement": { "trigger": "minecraft:impossible" } } }
what did i do wrong