itch.io

Hey there, you use the application "tiled". It's actually the "go to" for tilemaps. There is also a way to use tiled with godot, tho it depends on yxour programming, but you can also use them seperately. The application is free and can be found on itch too. I highly recommend using tiled for tilemaps and designing. The later maps can be exported and used via godot. I am not sure if it is supported natively, until know I usually programmed it into it.