How to code and program start key for Alfa Romeo Giulia

How to add remote start key to Alfa Romeo Giulia. There was a mixture of information on the internet and nothing on the key coding.
I hope I explain the process well as it had been a while since I had performed it for the first time.
If you have any questions comment below.
The key was a eBay special but it’s worked fine for the last 4-5 months. 

[@dienormaxjean]

why dont these keys have the "alfa romeo" chrome logo on the bottom? did they start cheaping out on the new keys or something?

[@Jackfi_89]

@@dienormaxjean the 3 button I changed the shell as the original was battered up and the 5 button is a aftermarket key. OE keys have the bottom AR logo.