Create GUI
Component Types
Shuffle: Click to cycle the options. The option currently selected is in the name of the item currently in the slot.
Link: Click on the item to open the selection menu. Make your selection by clicking any one of the options in the selection menu. The currently selected option will be shown in the name of the item in the main GUI.
Text: Click on the item to open an anvil GUI. Type your choice into the renaming box and click the green concrete in the result slot to submit.
GUI

Options
These are listed in order of being shown
World Like Selector
Type: Link
Sets the default behaviour of the dimension, based off an existing world.
World Identifier
Type: Text (Identifier)
Sets the Identifier of the dimension. Must be in the format of namespace:value
Difficulty Selector
Type: Shuffle
Sets the difficulty to be used in the world.
Seed
Type: Text (long)
Sets the seed of the chunk generator used in the dimension. Must be a numerical value (cannot contain letters)
Generator Type
Type: Shuffle
Sets the type of chunk generator used in the world.
Types
Noise: Standard chunk generator
Flat: Generates a flat world
Void: Generates a world with no terrain
Biome Source
Type: Link
Sets the biome source of the world. You can select the biome source of any of the existing worlds to be used
Fixed Biome Source
If you want your world to be a single biome, you can select the oak sign in the biome source menu. Enter the identifier of the biome you want to set the biome source.
Generator Settings
Type: Shuffle
Sets the shape of the terrain made by the generator.
Options
Overworld: Standard overworld terrain
Amplified: Amplified overworld terrain
Large Biomes: Large biomes overworld terrain
Nether: Nether terrain
End: End terrain
Caves: A world composed entirely of caves
Islands: A world composed of floating islands
Create
When finished, click the lime concrete to create your world.