CURLOPT_FTP_ACCOUNT man page
CURLOPT_FTP_ACCOUNT — set account info for FTP
CURLcode curl_easy_setopt(CURL *handle, CURLOPT_FTP_ACCOUNT, char *account);
Pass a pointer to a zero terminated string (or NULL to disable). When an FTP server asks for "account data" after user name and password has been provided, this data is sent off using the ACCT command.
The application does not have to keep the string around after setting this option.
Added in 7.13.0
Returns CURLE_OK if the option is supported, CURLE_UNKNOWN_OPTION if not, or CURLE_OUT_OF_MEMORY if there was insufficient heap space.