After those two changes everything works as it should. Remember to enter your ClientID and ClientSecret from Locitron App into the App Settings of the SmartThings SmartApp.
The above advise is for Lockitron Bolt. I created that advice when I first started playing with Smartthings. I have discovered that there may be a small snag in what I found.
I came across that URI when I went to the code screen in Smartthings IDE and ran the simulate function. Once you install the simulated App there will be an API Endpoint listed at the end. The Domain for this Endpoint is the Domain you need for the steps above. There are several possibilities depending on where you connect to the IDE site.It could be a different site for you.
Hope this advice is helpful. If you need more help I can add a step by step to how the process is done.
Apologies for never checking in on this (or some of the comments on GitHub). I’ll have a look and make some changes to the code. After I got my first Lockitron (this was the very very first ones that died after a day or so because the Wifi chip ate the batteries) I gave up. I decided with the battery drain and possible risk of the lock acting up and locking or unlocking inappropriately I decided that I don’t want an active lock on my door. (I am working to make something that just reports door lock state.)