You are attempting to purchase or redeem a download code for a game, content, or Nintendo Switch Online membership from the Nintendo website and receive error code 9001-0026.
This error code indicates that the Nintendo Account you are signed in to has not accessed Nintendo eShop from a Nintendo Switch console.
Nintendo Switch titles, content, and memberships can only be purchased or redeemed from the Nintendo website using a Nintendo Account actively linked to a Nintendo Switch console.
What to Do:
Verify you are logged in to the correct Nintendo Account on the Nintendo website or the offer page you are visiting.
Link your Nintendo Account to the Nintendo Switch console you wish to obtain the content on.
Access Nintendo eShop at least one time on the Nintendo Switch console using your Nintendo Account.
Return to the Nintendo website or the offer page and attempt to purchase or redeem the content again.