Why does roblox studio walk wrong through the table

I am making a game right now in roblox, and need to make gamepass store, however when my loop goes through it (its a table in table), it goes out of order Example code with the tables in table

a = {
    ["5robux"] = {
        value = 10,
        name = "21"
    },
    ["10robux"] = {
        value = 13,
        name = "31"
    },
    ["15robux"] = {
        value = 20,
        name = "41"
    },
    ["20robux"] = {
        value = 25,
        name = "64"
    },
    ["61robux"] = {
        value = 25,
        name = "64"
    },
    ["50robux"] = {
        value = 3,
        name = "64"
    }


}
for i, v in pairs(a) do
    print(i, v)
end

Output:

5robux  ▶ {...}  -  Server - Script:30
50robux  ▶ {...}  -  Server - Script:30
61robux  ▶ {...}  -  Server - Script:30
20robux  ▶ {...}  -  Server - Script:30
15robux  ▶ {...}  -  Server - Script:30
10robux  ▶ {...}  -  Server - Script:30

As you see, it firstly goes to the first element, then to the last and so on

Also tried removing the brackets [], got another output which is still incorrect Output:

robux15  ▶ {...}  -  Server - Script:30
robux5  ▶ {...}  -  Server - Script:30
robux50  ▶ {...}  -  Server - Script:30
robux61  ▶ {...}  -  Server - Script:30
robux10  ▶ {...}  -  Server - Script:30
robux20  ▶ {...} 

How can i fix it, and whats wrong?

Tried changing the loop, but still wrong output

Dictionaries in Lua aren't in order, only arrays are. If you want to be able to iterate over it in the correct order try something like

a = {
    {
        key = "5robux",
        value = 10,
        name = "21"
    },
    {
        key = "10robux",
        value = 13,
        name = "31"
    },
    {
        key = "15robux",
        value = 20,
        name = "41"
    },
}
for i, v in ipairs(a) do
    print(i, v.key)
end

Which will output this

1   5robux
2   10robux
3   15robux