Dark Oak Leaves are foliage blocks harvested from dark oak trees, which are typically found in the roofed forest biome. These blocks can be collected with shears or by using a tool enchanted with Silk Touch. When destroyed without the appropriate tool, they have a chance of dropping saplings, which players can use to grow new dark oak trees, or rarely, apples. They also decay naturally if not connected to a log block, simulating real-life leaf drop.
This item has no numerical item ID, therefore you must use the item ID to spawn the item. Numerical item IDs were removed in Minecraft version 1.13.
The item id for Dark Oak Leaves is minecraft:dark_oak_leaves
The item ID for Dark Oak Leaves is minecraft:dark_oak_leaves
This is the spawn command to give yourself Dark Oak Leaves in Minecraft which includes the Minecraft /give command. If you are using the Essentials plugin you will need to use /minecraft:give instead of /give