The item ID for Ancient tree(unbreakable) is SwampTree2
This is the spawn command to give yourself Ancient tree(unbreakable) in Valheim normally without the level option.
Copy the command below and paste it into your Valheim game or server admin console to obtain.
This is the spawn command to give yourself Ancient tree(unbreakable) in Valheim with the level option if applicable. Below is just an example with the item chosen. Some items do not have leveling.
Copy the command below and paste it into your Valheim game or server admin console to obtain.