Minecraft Flat World on the switch?

I need help!

I have the Minecraft Bedrock Edition for the switch. I would like to make a Custom Flat World, so that the world of Bedrock is x25 blocks high. However, this is only possible if I have a seed of Minecraft: Nintendo Switch Edition, but I do not have them and can't buy them in eShop or in the store! 😞

Maybe someone can help me or someone else has the Minecraft: Nintendo Switch Edition! Then I would ask him a world with x1 bedrock and then x24 times earth and then x1 grass. I would be glad if this Seed writes with an answer to my comment, but ONLY if you have the Minecraft: Nintendo Switch Edition, Thanks! 😊

You can also use the / fill command to fill in all the blocks you need. Then you do not need a seed. ^^

Unfortunately, this is very creeps because you can only make about 32,000 blocks and that is very little.

use mod?

idk how to do this i have bedrock on minecraft on the nentendo i have bin trying for ages i hope you can find a way if so please tell me how