How to make a code activate only 1 time no matter how many times you reopen the app?

how to make a code activate only 1 time no matter how many times you reopen the app it just activates 1 time per device?
my codes

Have a spreadsheet row that looks like this:

[code] [used?]

Start with values like this:

12345 no

When the user enters a code, check if the 2nd column for that code is “no”. If it is, change it to “yes”. If it isn’t, then don’t allow them to use it.

That will allow that code to be used once across all devices (only once on a single device, then not on any other devices).

If you want the code to work once on every device, use a stored variable for the “used?” value instead.

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