The ‘Missing Credentials‘ error occurs when the sheet is unable to recognize your details, such as when you have not entered your Account ID or have entered it incorrectly.
The error you will get is Missing Credentials (line ****). or in some cases you get Missing Amazon Credentials (line ****).
​Please verify or add the Account ID by navigating to Extensions > Amazon Seller Central Connector – Gorilla ROI > Add Account ID and see if the functions work correctly.