Gumroad

1. In Gumroad, create one offer code per tier. Match the percent to the tier discount in FairPrice, and use the same code string.
2. Copy Gumroad’s discount link. It has historically used offer_code on the product URL. Confirm the parameter in Gumroad’s current discount screen before you launch.
3. Set FairPrice’s redeem URL to that link, with the code replaced by {code}.
4. Paste the script on the site you own — the landing page, docs, or a page you link from the product description.

https://you.gumroad.com/l/your-product?offer_code={code}

Copying the code still works if you leave the redeem URL empty. The buyer pastes it into Gumroad’s discount field. The banner stays hidden for full-price countries and for VPN, proxy, or datacenter visitors, and those responses contain no code. A visitor who was shown the code can still share it, so set a quantity limit on the offer code. Test from a residential connection or use the dashboard preview.