Hi, I am doing something wrong?, I'm using the tools to select 2 points, then enter the block ID when using the fill GUI, but the fill button remains grayed out.

Minecraft 1.19, the latest forge and mod installed from curse forge.

Thank you.

What text do you enter? The button should automatically enable itself if you enter a vaild block resource location i.e. 'grass_block' or 'minecraft:stone'. Note that spaces will be automatically replaced with '_'.

Thank you for your response, I want to use it to delete blocks so I tried using: minecraft:air, air alone, and 0.
It works with cave_air and void_air, but i really don't know if i can use it the same way or they are for different purposes.

Yes that must be an oversight by me in the 1.19 port. I will fix that later today. Thank you for the report.