Can´t store an Item on an Armor Stand

When trying to store my selectet Item to an armorstand the output is only the item holding in hand.

Command: /execute store result entity @e[type=minecraft:armor_stand,limit=1,tag=test] HandItems[0] byte 0 run data get entity @a[tag=player,limit=1] SelectedItem

Output: [CHAT] Quipsi besitzt die folgenden Objektdaten: {id: "minecraft:netherite_sword", Count: 1b, tag: {Damage: 0}}