Give mobs effect on right click

[skriptKiddie]

Skript Version (do not put latest): 2.4-MH

Skript Author: LetItDie & skriptKiddie
Minecraft Version: 1.15.1
---
Full Code:

on right click:

    # Check if it's the right tool
    name of the player's weapon is "[Harmonia]"
    tool of player is blaze rod
   
    # Check if player has a cooldown
    set {_waited} to difference between {harmonia.%player%.lastused} and now


    # If the cooldown is less than 120 seconds, tell them
    if {_waited} is less than 120 seconds:
        message "&8[&c!&8] &7You must wait &c%difference between 120 seconds and {_waited}% &7until you can use Harmonia again" to player

    # If it is more, proceed
    if {_waited} is more than 120 seconds:

        # Reset timer
        set {harmonia.%player%.lastused} to now

        loop all entities in radius 6 around player:
            apply slowness 4 to loop-entity for 30 seconds
            apply weakness 4 to loop-entity for 30 seconds
        remove slowness from player
        remove weakness from player

What's meant to happen: On right click with a blaze rod named "[Harmonia]", all mobs in a certain radius are meant to receive slowness and weakness for a few seconds.

What actually happens: Nothing actually happens on right click

There are no console errors and no errors on reload. I am not currently using any addons and I have tried to search the docs.