I am guessing you mean how do you connect via a browser?
Because it's an ftp server, you'll need to tell the browser you are needing to connect using the ftp protocol, do that with:
Then follow that with your public IP, you can obtain that from:
And finally put them together:
And the browser should be able to pull them up. This certainly assumes your ISP hasn't blocked port 21. If it has, you have a few options, but we'll wait to go there.
To find out what ports you have open and available, head over to:
And take their Sheilds UP! Test and check out the ports available and their condition.