I'm trying to figure out how to use their API, and am trying to make a simple GET request on an item, but getting an "Invalid access token" response. Their documentation is terrible, but what I tried is to get a prod user token with Auth'n'Auth by signing into a prod eBay user account from the dev console. That gives me a "user token". Then I include that user token in my header and using the prod endpoint, but receiving the invalid access token response. Does anyone know what I'm doing wrong here? Below is my request.
GET https://api.ebay.com/sell/inventory/v1/inventory_item/303769339544 Content-Type: application/json Authorization: Bearer <USER TOKEN> X-EBAY-C-MARKETPLACE-ID:EBAY_US