CURLOPT_PROXYPASSWORD man page
CURLOPT_PROXYPASSWORD — password to use with proxy authentication
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_PROXYPASSWORD, char *pwd);
Pass a char * as parameter, which should be pointing to the zero terminated password to use for authentication with the proxy.
The CURLOPT_PROXYPASSWORD(3) option should be used in conjunction with the CURLOPT_PROXYUSERNAME(3) option.
The application does not have to keep the string around after setting this option.
Added in 7.19.1
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.
CURLOPT_PASSWORD(3), CURLOPT_PROXYUSERNAME(3), CURLOPT_HTTPAUTH(3), CURLOPT_PROXYAUTH(3)