error t_httpUpdate_return ret = ESPhttpUpdate.update (update_server, 80, update_uri, firmware_version);

[paolobugiani]

hello, I have this problem on this line:
t_httpUpdate_return ret = ESPhttpUpdate.update (update_server, 80, update_uri, firmware_version);

I have this error:

exit status 1

no matching function for call to 'ESP8266HTTPUpdate :: update (const char * &, int, const char * &, const char * &)'

can you help me? Thanks