How to offer protect a page and sell access through coupon

Okay, I think I managed to distill the issue one way.

I have an on-line questionnaire. I want to sell access to it. That’s easy.

Harder….. I haven’t figured out how to do this

Purchaser A buys a “gift certificate/token/coupon” which is can give to another to have that person gain access to the questionnaire for free.

Woo commerce had too many bells and whistles but I tried to get it to work for me.
What would be an easy way to code it? Do it? Came here for help, been looking everywhere for a way to do it.

Thanks