Give Creators the Ability to Manually Assign Licenses

When transferring from one platform (such as Gumroad) to here, many users would like to be able to keep the licenses they already purchased.

I would like to recommend a feature for creators that allows them to directly assign a license to an email without going through the purchase steps. At the time of writing, I am not aware of any way to securely do this on Jinxxy without giving each user an individual discount code. (This method could be abused by clients.)

Ideally, it would be easiest to be able to list many emails at once, but if it has to be 1 by 1, that would work too.