How do I set up a remote desktop connection with 2X Client Portable?

I've tried setting up a remote desktop connection myself and the program always fails to connect. I don't know what I am doing wrong and I can't find any guides or tutorials for this program. Is there anyone else here who uses this program, if so, where can I go to get help with this program?

Link to 2X Client Portable: https://portableapps.com/apps/utilities/2x_client_portable