You need to create a seller account. Before you can list this item we need some additional information to create a seller account.
Though many fellow developers have asked the same question but I am still not able to find the reason and solution of this error. Whenever I am trying to post my product listing on sandbox account I getting this error my username is : testuser_shivrag my developer account username is : bitsey1 How can I convert testuser_shivrag user to seller account ? Can anyone help me on this ?
Hi @devesi-7397, Apologies for the inconvenience. We are facing temporary issue to Sandbox once you get it fixed we will do PayPal Sandbox Linking for your account and let you know Best regards, eBay Developer Support