Connecting to my locally running ftp server written in golang

I am trying to use this ftpserver on Ubuntu. I am able to start the server as in below screenshot but I don’t know how to connect to it when it’s running. I tried ftp [IP] command which I found online, since it is running on my laptop I used 127.0.0.1 as the IP and 2121 as port but failed to connect. If I just type ftp I get the ftp> prompt but I think it is the ftp server provided by Ubuntu and not the one I started. Please advice how to use the server.