"
They have smart phone apps, so I guess the person in the place you are going to tells you the three words.

Ummm... so **someone** has to have a smart phone and an 'app' in this process? It sure won't be me, as I have neither. There are too many requirements for everyone involved to share certain information, understanding and software/hardware. (Like Cockney rhyming slang needing previous sharing of connection.)