It's keep saying Invalid transformation.
I was searching in documentation but found nothing.

#sel expand a/n/o up/down numberofblocks
a stands for all n for new and o for old (selections)

Thanks, you help me a lot! I use it to make tunnel, and seal walls.

is there any way to expand it sideways

is there any way to expand it sideways

You can use cardinal directions (north, south, east and west) in place of up or down.

#help sel should show this info

#sel expand a/n/o up/down numberofblocks a stands for all n for new and o for old (selections)

it doesnt work
invalid transform type