Http Request Post my api system inside to lua

Hi guys , i need help i have hosting i write own api system.

This my code;

local sunucuno = 'duzenleyiniz.'
   local hex = identifiers[1]
 PerformHttpRequest(''..sunucuno..'&steamhexid='..hex..'', function(err, text, headers)

I don’t know how to configure post and add User-Aget because my host have firewall every time I need user-agent “Mozilla/5.0 (compatible; MSIE 9.0; Windows NT 6.1; Trident/5.0)”;

Soneone help to me pls ?

Guys ?

its must be like this