Zymkey 4 not working on CURL

Hi,
I have recently bought the zymkey 4 and installed in on my raspberry Pi. I have successfully created the CSR using openSSL command and created a device certificate in AWS. When I am trying to use CURL to send data using MQTT its giving an error Private key not found. It seems like Curl is unable to access the nonzymkey.key file.

This is the command I am trying:-

curl --tlsv1.2 --cacert AWS_CA.pem --cert zymkey.crt --key nonzymkey.key --engine zymkey_ssl --key-type ENG -v -X POST -d “{ "hello": "world"}” “https://example1.iot.us-east-1.amazonaws.com:8443/topics/hello/world

the output I am getting:-

$ curl --tlsv1.2 --cacert AWS_CA.pem --cert zymkey.crt --key nonzymkey.key --engine zymkey_ssl --key-type ENG -v -X POST -d “{ "hello": "world"}” “httpx://ddddddd.iot.us-east-1.amazonaws>com:8443/topics/hello/world”
Note: Unnecessary use of -X or --request, POST is already inferred.

  • Trying xx.xx.146.237:8443…
  • Trying ::3656:df64:8443…
  • Immediate connect fail for:3656:df64: Network is unreachable
  • Trying::3456:b692:8443…
  • Immediate connect fail for ::3456:b692: Network is unreachable
  • Trying ::3654:2721:8443…
    ** Connected to test.iot.us-east-1.amazonaws>com (xx.xx.146.237) port 8443 (#0)
  • ALPN, offering h2
  • ALPN, offering http/1.1
  • successfully set certificate verify locations:
  • CAfile: AWS_CA.pem
  • CApath: /etc/ssl/certs
  • TLSv1.3 (OUT), TLS handshake, Client hello (1):
  • TLSv1.3 (IN), TLS handshake, Server hello (2):
  • TLSv1.2 (IN), TLS handshake, Certificate (11):
  • TLSv1.2 (IN), TLS handshake, Server key exchange (12):
  • TLSv1.2 (IN), TLS handshake, Request CERT (13):
  • TLSv1.2 (IN), TLS handshake, Server finished (14):
  • TLSv1.2 (OUT), TLS handshake, Certificate (11):
  • TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
  • TLSv1.2 (OUT), TLS alert, internal error (592):
  • error:100F907D:elliptic curve routines:ossl_ecdsa_sign_sig:missing private key
  • Closing connection 0
    curl: (35) error:100F907D:elliptic curve routines:ossl_ecdsa_sign_sig:missing private key

Security Module for Raspberry Pi