> ## Knowledge Base Index
> Fetch the complete knowledge base index at: https://support.trackingmore.com/sitemap.xml
> Use this file to discover available pages before exploring further.
> Pure-Markdown content can be obtained by appending a '.md' suffix to the content URLs listed in the sitemap (without the trailing slash).

# Why do I get 401 response code error?

401 response code error occurs when authentication failed or has no permission no matter which TrackingMore API version is. 
Please check and ensure you are under a paid plan & your API Key is correct.