gift card not working in my region

i used the code from a gift card sent to me by my friend, it says it's unable to be used in my country, tells me to go to https://support.riotgames.com/hc/en-us/requests/new and look for help, but when i open it, it just shows this. my friend and i live in different countries, and the gift card is a physical one, if that helps.