When I try to set "Home" on my Garmin i3 satnav, it asks if I want to enter an address. I don't, I want to add a Favourite which doesn't have an address as it is "off road".

How can I do that either when I'm next there or, preferably, when I'm not actually there - i.e. "remotely"?

Many thanks from a satnav technophobe.