Players without op can't use a command with no required permissions

[SuperTommyDog]

So i found out only people with op can open the shop beyond the initial page. I am very confused as it has no permissions which are required. Here is the code.https://pastebin.com/iThM0Jmp

 

[Minecoll_YT]

Not sure what you mean, there is no check if the player has a permission. And SkQuery GUIs are a big no, convert Vanilla GUIs.
For stuff like this you better use functions, for example:

function shop(p: player, category: text):
    if {_category} is "main":
        # do your category stuff
    else if {_category} is "redstone":
        # add redstone
    # just copy & paste to continue

command /shop [<text>]:
    trigger:
        shop(player, "main")

And a little advice on how to shorten things down:

            # wrong
            set {_slot} to 0
            loop 54 times:
                format gui slot {_slot} of player with gray glass named "&7"
                add 1 to {_slot}

            # right
            format gui slot (integers from 0 to 54) of player with gray glass named "&7"