ESP8266 sending data to web server

I need to make an WEB based monitoring system using ESP8266, which could display the data. The system will have a user registration form, which should allow to display the data for a particular user. For this purpose I got a remote server (domain). Now I'm facing with some problems, how could I send data to this domain from the ESP? My ESP module uses NodeMCU firmware and I can program it using Lua. I read that there is HTTP GET and POST request methods and I unsuccessfully spent a few days trying to implement one of these methods... Maybe someone could put me on the road What should be the sequence of steps to start sending data to the external server? That would be a big step forward if I could send f.e. constant value variable.