$ curl --insecure --proxy proxy.crawlera.com:8010 -u "<API_KEY>:" --location https://httpbin.org/ip -v
*   Trying 64.58.117.143...
* TCP_NODELAY set
* Connected to proxy.crawlera.com (64.58.117.143) port 8010 (#0)
* Establish HTTP proxy tunnel to httpbin.org:443
* Server auth using Basic with user '<API_KEY>'
> CONNECT httpbin.org:443 HTTP/1.1
> Host: httpbin.org:443
> User-Agent: curl/7.54.0
> Proxy-Connection: Keep-Alive
>
< HTTP/1.1 200 OK
<
* Proxy replied OK to CONNECT request
* ALPN, offering h2
* ALPN, offering http/1.1
* Cipher selection: ALL:!EXPORT:!EXPORT40:!EXPORT56:!aNULL:!LOW:!RC4:@STRENGTH
* successfully set certificate verify locations:
*   CAfile: /etc/ssl/cert.pem
  CApath: none
* TLSv1.2 (OUT), TLS handshake, Client hello (1):
* TLSv1.2 (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, Server finished (14):
* TLSv1.2 (OUT), TLS handshake, Client key exchange (16):
* TLSv1.2 (OUT), TLS change cipher, Client hello (1):
* TLSv1.2 (OUT), TLS handshake, Finished (20):
* TLSv1.2 (IN), TLS change cipher, Client hello (1):
* TLSv1.2 (IN), TLS handshake, Finished (20):
* SSL connection using TLSv1.2 / ECDHE-RSA-AES256-GCM-SHA384
* ALPN, server did not agree to a protocol
* Server certificate:
*  subject: CN=httpbin.org
*  start date: Apr 11 21:05:41 2019 GMT
*  expire date: Apr  8 21:05:41 2029 GMT
*  issuer: C=IE; ST=Munster; L=Cork; O=ScrapingHub; OU=Leading Technology and Professional Services; CN=Crawlera CA; emailAddress=support@scrapinghub.com
*  SSL certificate verify result: unable to get local issuer certificate (20), continuing anyway.
* Server auth using Basic with user '<API_KEY>'
> GET /ip HTTP/1.1
> Host: httpbin.org
> Authorization: Basic <API_KEY__BASIC_AUTH>
> User-Agent: curl/7.54.0
> Accept: */*
>
< HTTP/1.1 407 Proxy Authentication Required
< X-Crawlera-Error: bad_proxy_auth
* Authentication problem. Ignoring this.
< Proxy-Authenticate: Basic realm="Crawlera"
< Content-Length: 0
< Date: Fri, 12 Apr 2019 21:43:35 GMT
* HTTP/1.1 proxy connection set close!
< Proxy-Connection: close
< Connection: close
<
* Closing connection 0
* TLSv1.2 (OUT), TLS alert, Client hello (1):