First rule of home automation applies: “the model number matters.“
Unfortunately, the 914 is one of the older models, and does not support zwave “SmartStart.” Which is the QR code method that was mentioned.
The model name is “SmartCode,” but that’s just a name that KwikSet made up before “smartstart” was added to the independent third-party protocol. So not the same feature. 
https://products.z-wavealliance.org/products/3101?selectedFrequencyId=2
In any case…Zwave devices were designed to be used without any app at all if necessary. So the person who is physically present, whether this is a lock that supports the smartstart zwave feature or not, doesn’t need the app. As @Automated_House mentioned, you can be 1000 miles away and use the app and your app will communicate to the smartthings cloud which will communicate to the hub at the physical location.
But…as @nathancu mentioned, whether you are using a lock that supports the SmartStart feature or not, someone has to be physically present to do something with the lock as a security precaution.
The Zwave SmartStart Feature
If the lock is one of the newer models that support SmartStart, The goal was to make the process as easy as possible on site. So you use the QR code through the app to preload the lock information into the hub. (Their original idea was that companies would be able to do this back at the office without even opening the box for the lock or having to power it up.)
Then as soon as the lock is physically installed AND powered on, it will check to see if there is a nearby hub which already has its information. This process can be pretty slow, it may take 10 or 15 minutes. But it all happens automatically, so easier than the old method.
But somebody has to be present to at least put the batteries in the lock, (or take them out and put them back in if they were previously in place). So that’s the security precaution at the time the device is being added to your network.
But that person doesn’t need the account credentials or an app. And they don’t even need to be on the phone with the person who does have the app. As long as the QR code is entered through the app before the batteries are put in the lock, and there’s been time for the hub to get the information, the next time the lock powers up, it will add itself to the Network. Again, the whole idea of the smartstart feature was to simplify installation. A security company could do all the set up work back at their office, then give an installation pack to their installer or even mail it to the homeowner, and once the lock was physically installed, it would add itself.
Without SmartStart
However… The model number matters, and your model can’t do that. Which means you have to synchronize using the app with the physical manipulation of the lock. The two people don’t have to be in the same building, and the one who is physically handling the lock doesn’t have to have the app, but they would have to be talking on the phone and doing things in the right order at about the same time. So I don’t know if that helps you or not. It’s a little easier than you were imagining since the person in the building with the lock doesn’t have to have the app at all, but you do still have to have a person physically there. 
