With some modifications to the script itself it can be setup like..

Users register but cant login until an admin activates the account (This feature is already built in)

Now for what would be needed:
When activated by the admin the date activated is recorded, and some code is set to execute every night to check if a year (or whatever subscription term you want) has passed, if it has deactivate the account (or delete if you really wanted it to). Then if the user wanted another subscription they would pay and the admin would reactivate the account, the time would be reset to the present date, and they would have another term.
Also something like a renew button could be added in the admin panel to reset the time to have an additional term added before the subscription would expire


But the script itself, as it is now does not have this feature built in, it would require modifying the script

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Register/Login Script
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