Execute unless block, not functioning

[BlackTiger007]

If I

execute.as("@e[type=minecraft:marker,tag=test]").at("@s").unless.block(["~", "~", "~"], "minecraft:dropper").run. setblock(["~", "~", "~"], "minecraft:dropper[facing=up]", "destroy")

we end up making it unless block ~,~,~ minecraft:dropper but only one unless with if it works.