Error 2813-6561 means your Nintendo download code was entered incorrectly or is intended for a different region's eShop. First re-enter the code carefully — Nintendo codes are 16 characters and the letters I, O, and Z are never used. If the error persists after re-entering, the code is from the wrong region. Check your Nintendo Account region at accounts.nintendo.com → Profile → Country/Region, and compare it to the code region (ESRB = Americas, PEGI/USK = Europe). Contact the seller for a replacement in the correct region, or create a new Nintendo Account set to the code's region to redeem it there.
