Give same code to user each time they download

I would like to create a function that hooks to “voucher_download” and checks to see if the current user has downloaded this voucher before. If no then issue a new code. If yes then insert their previous code into the voucher.

Basically, only allow one code per user but allow the user to download the voucher more than once.

Any hints on how to accomplish this?

Thank you! I’ve donated to this great plugin.

Cheers,
John.

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