Please close solved.

[outer steeple]

how to disable player movement without server kicking player for fly ?

[lethal belfry]

command /sitdown [<text>]:
    trigger:
        if arg 1 is set:
            loop all players:
                if arg 1 is "true":
                    set {_} to 1
                    while air is {_} of block below location of loop-player:
                        add 1 to {_}
                    set {_pos} to {_} of block below location of loop-player
                    teleport loop-player to {_pos}
                    set {no-move::%loop-player%} to true
                if arg 1 is "false":
                    delete {no-move::%loop-player%}
on player move:
    cancel event if {no-move::%player%} is set```
I'm not sure if that's what it is, but it should work

/sit down true - can't move
/sit down false - can move

[true girder]

you need to disable the flying kick in server.properties im pretty sure

[midnight sky]

any fly hacks will normally bypass the fly check in server.properties

dont think it matters imo