How would I describe this value? (I'm very new to scripting by the way.)

I have a script that is trying to send command data from a GUI over to another script to run the command. This script below only happens when the enter/return key is pressed. But the "enterPressed:Connect(get_command)" doesn't want to work because it doesn't know if I'm pressing the enter/return key and always gives me an error. Is there any way that I could describe this better so that the script picks up that that is part of it?

Easier to read Version: The "enterPressed:Connect(get_command)" keeps giving me errors and I don't know what to do about it. It is trying to send data from a GUI over to another script to be used in a command. The other way this worked was with a GUI where it was "enter.MouseButton1Click:Connect(get_command)" which would send it over to the other script and work. I would like to do just that but with a keypress from the user's keyboard.

If I didn't give enough detail please tell me. I did just start to learn how to script about a month ago and most of this script was a tutorial.

CommandBox.FocusLost:Connect(function(enterPressed)
    if enterPressed then
        script.Parent.Visible = false
        enterPressed:Connect(get_command)
    end
end)

Full script:

local rs = game:GetService('ReplicatedStorage')
local commandEvent = rs:WaitForChild('CommandEvent')

local frame = script.Parent
local box = frame.CommandBox



--list of valid commands

local actions = {

    ';kill' , ';freeze' , ';unfreeze' , ';hide' , ';show' , ';speed', ';jump',

    ';trail', ';goto', ';find', ';kick'

}

local needValue = {

    ';speed', ';jump'

}

local function valid_command(action)
    for _,command in pairs(actions) do
        if command == action then
            return true
        end
    end
end

local function valid_player(person)
    local player_table = {}
    if person == 'me' then
        local player = game.Players.LocalPlayer
        table.insert(player_table, player)
    elseif person == 'all' then
        player_table = game.Players:GetChildren()
    elseif person == 'others' then
        player_table = game.Players:GetChildren()
        for _, admin in pairs(game.ReplicatedStorage.Admins:GetChildren()) do
            for pos, plr in pairs(game.Players:GetChildren()) do
                if admin.Name == plr.Name then
                    table.remove(player_table, pos)
                end
            end
        end
    else
        local player = game.Players:FindFirstChild(person)
        if player then
            table.insert(player_table, player)
        else
            return false
        end
    end
    return player_table
end

local function valid_value(action, value)
    for _,command in pairs(needValue) do
        if command == action then
            if not value then
                return false
            end
        end
    end
    return true
end

local function get_command()
    local command = {}
    for word in string.gmatch(box.Text, "%S+") do
        table.insert(command, word)
    end

    local action = command[1]
    local person = command[2]
    local value = command[3]

    box.Text = ''

    if valid_command(action)then
        local player_table = valid_player(person)
        if player_table then
            if valid_value(action, value) then
                commandEvent:FireServer(action, player_table, value)
            else
                box.Text = 'Value Error'
            end
        else
            box.Text = 'where did that player even go? [Invalid Player]'
        end
    else
        box.Text = 'hang on i have the list somewhere [Invalid Command]'
    end
end

CommandBox.FocusLost:Connect(function(enterPressed)
    if enterPressed then
        script.Parent.Visible = false
        enterPressed:Connect(get_command)
    end
end)