These are the commands I mention at the title, please help me clarify its function:
/jump lock
/kittycannon
/nuke
Thanks
*I already know /kittycannon and /nuke are related to explosion, but what kind of it? I used to heard a command that make a TNT rain

/jump lock makes you teleport whenever you click on a block.

/kittycannon fires (non-damaging) exploding kittens in the direction you are facing.

/nuke causes TNT to rain down from the sky around each player.

the tnt dropped by /nuke has never been damaging on my server? I thought it wasn't supposed to do damage?

@md678685 and essentials.pvpdelay.exempt, what it suppose to do? I can't find anything as "pvp_delay" in the config files, but the description said "Exempts players from the 'pvp delay' option in the config file."

It probably excempts you from the join or teleport PvP delay

And the /jump lock? I can't use this command to right click teleport to block, and essentials.pvpdelay.exempt. As you said it definitely need to use luckperm timed permission to work right? I said that I can't find the exact "pvp_delay" or sort of that in the config file, if I add this permission to a player, does it mean he is protected by pvpdelay.exempt forever?

It probably excempts you from the join or teleport PvP delay

Correct, this is what it does.

Hello again, sorry for disturbing-but somehow /jump lock command hasn't work as intended

@ProblemsSender Please open and fill out a support request.

/jump lock makes you teleport whenever you click on a block.

/kittycannon fires (non-damaging) exploding kittens in the direction you are facing.

/nuke causes TNT to rain down from the sky around each player.

Hello again, sorry for disturbing-but somehow /jump lock command hasn't work as intended, here's my ess versions
[14:04:41 INFO]: Server version: 1.12.2-R0.1-SNAPSHOT git-Spigot-dcd1643-e60fc34
(MC: 1.12.2)
[14:04:41 INFO]: EssentialsX version: 2.15.0.57
[14:04:41 INFO]: PermissionsEx version: 1.23.4
[14:04:41 INFO]: Vault version: 1.6.7-b${env.TRAVIS_BUILD_NUMBER}
[14:04:41 INFO]: EssentialsXProtect version: 2.15.0.57
[14:04:41 INFO]: EssentialsXSpawn version: 2.15.0.57
[14:04:41 INFO]: EssentialsXChat version: 2.15.0.57
[14:04:41 INFO]: EssentialsXAntiBuild version: 2.15.0.57

Pls help me make this command to work, is this required some config to work? At first I thought that my problem is I didn't give my player a permissions to build.* - I added that and it still appear, what is the requirement to make this work? And additional question, can we use /jump lock instead of /jump?