Hostname and iPad

I have a simple but irritating problem when setting up the terminal connection from an iPad. Would the hostname be http://(plus my IP address)? I ask because no combination of the settings appears to work. 

No matter how simple I make the password/username, they’re unrecognized and when I try the public key, I don’t have authorization. 

So... since I want the terminal to work without any ID or password, I am assuming that I’ve wrongly configured the iPad’s hostname. You have the example of textastic.com, I think... but what’s the structure of an end-user such as myself? 

I presumed it was the IP address, expressed as a URL— and that brings me back to the start of my message :-) 

Thanks