These mushroom cant be destroyed.
https://www.reddit.com/r/valheim/comments/m3cv2d/spent_hours_building_and_accidentally_spawned/
So you have to install this mod and all credit to the modder for making it.
https://www.nexusmods.com/valheim/mods/933
I will never use it lol instead the yellow mushroom will do fine with a small stand crafted on a table.
https://steamcommunity.com/sharedfiles/filedetails/?id=2481598871