I am able to generate access_token using command line example npx @jkhy/banno-client-creds-helper client-assertion --client-id=[CLIENT-ID] --private-key=private.pem successfully but unable to generate the access_token using Postman.
Below is the request and response when using https://banno.com/a/oidc-provider/api/v0/token API using Postman.
"Request Body": {
"client_assertion": "xxxxxxxxxx", (client_assertion generated using command line)
"client_assertion_type": "urn:ietf:params:oauth:client-assertion-type:jwt-bearer",
"grant_type": "client_credentials",
"scope": "openid",
},
"Response Headers": {
"date": "Tue, 12 Apr 2022 16:35:50 GMT",
"content-type": "application/json; charset=utf-8",
"content-length": "77",
"connection": "keep-alive",
"x-request-id": "23573ece09990d419df945b263c80004",
"x-b3-traceid": "353fcf7b7908a447",
"x-b3-spanid": "2579854fba7e468c",
"x-b3-sampled": "1",
"access-control-allow-origin": "*",
"x-b3-parentspanid": "e87977b8a21d048b",
"pragma": "no-cache",
"cache-control": "no-cache, no-store",
"x-envoy-upstream-service-time": "102",
"strict-transport-security": "max-age=15724800"
},
"Response Body": "{\"error\":\"invalid_client\",\"error_description\":\"client authentication failed\"}"