Older Etsy examples may fail for a reason unrelated to the user's authorization. Since February 9, 2026, Etsy requires x-api-key to contain the keystring and shared secret separated by a colon. Calls requiring OAuth still need their OAuth credentials and appropriate scopes. See the official request requirements.
Use the Etsy directory entry to discuss which operation is failing, then check the application header and user authorization separately. Keep the shared secret on the server; copying a formerly public-key-only example into browser code is not a safe migration.
Akousa