-k, --insecure
          (TLS SFTP SCP) By default, every secure connection curl makes is
          verified to be secure before the transfer takes place. This  op‐
          tion  makes  curl skip the verification step and proceed without
          checking.

          When this option is not used for protocols using TLS, curl veri‐
          fies  the server's TLS certificate before it continues: that the
          certificate contains the right name which matches the host  name
          used in the URL and that the certificate has been signed by a CA
          certificate present in the cert store.  See this online resource
          for further details:
           https://curl.se/docs/sslcerts.html

          For  SFTP  and  SCP, this option makes curl skip the known_hosts
          verification.  known_hosts is a  file  normally  stored  in  the
          user's home directory in the ".ssh" subdirectory, which contains
          host names and their public keys.

          WARNING: using this option makes the transfer insecure.

          When curl uses secure protocols it trusts responses  and  allows
          for  example  HSTS and Alt-Svc information to be stored and used
          subsequently. Using -k, --insecure can make curl trust  and  use
          such information from malicious servers.

          Providing  -k,  --insecure  multiple  times has no extra effect.
          Disable it again with --no-insecure.

          Example:
           curl --insecure https://example.com

          See also --proxy-insecure, --cacert and --capath.