Hi Resan,
Thanks for reaching out! From the code sample you sent, it looks like you’re trying to hit the auth endpoint using a GET HTTP method. As indicated in the error message below, you need to use a POST HTTP method.
< HTTP/1.1 405 Method Not Allowed
and
< Allow: POST,OPTIONS
For more information, please visit the DPC documentation page at https://dpc.cms.gov/docsV1#obtain-an-access_token.
We hope this information helps, please let us know if you have further questions.
Best,
The DPC Team