Receiving an Item on a Specific Page?

[Sibyl]

How can I make it so that my users can receive a specific item for going onto a certain page? And, better yet, make it so they can only receive said item once? ;~;

I'd love to do an exploration type system, but I'm uncertain of how to make it rewarding without the user having to be redirected to a shop so they can buy the item themselves, or make it so that there is a promo code. The problem with promo codes is that the user must leave the page to go enter the code, and they could share the codes with the other users. ;~~~;

If anyone knows even a makeshift way, that'd be wonderful ;v; thank you all very much.