HOW-TO: Pair and Connect your Amazon Echo with a Schlage Lock via a Samsung SmartThings Hub
HOW-TO: Pair and Connect your Amazon Echo with a Schlage Lock via a Wink Hub 2
HOW-TO: Pair and Connect your Amazon Echo with a Yale Z-Wave Lock via a Samsung SmartThings Hub
HOW-TO: Pair and Connect your Amazon Echo with a Yale Z-Wave Lock via a Wink Hub 2
Sorry, but this is a very misleading post to have in this particular forum and it is going to confuse a lot of people. 
We spend a lot of time in this forum helping people understand the basic concept of how their SmartThings system works. Videos of this type are both imprecise and confusing in this regard.
First, let’s get one thing very clear: it is impossible to “pair” a lock of the type shown to echo. It doesn’t have a Z wave or zigbee radio. Instead, you connect your Amazon account to your SmartThings account and pass requests made to the echo over to the SmartThings cloud. That’s a really important difference, and we work hard in this forum to make sure that people understand that difference.
Next, these videos will trigger someone’s Amazon echo. That’s both annoying and in some cases unsafe. So you should always have a warning on the video that that is going to happen.
Finally, these videos only demonstrate the native echo features, which is why you say that it is not possible to have echo unlock the door. However, there are indeed many ways to have echo unlock the door if you have SmartThings. I’m not saying that everyone will want that, but absolutely it can be done. And there are multiple threads here explaining how to do it. It’s a very good demonstration of the power and flexibility of the SmartThings system. So it is inappropriate to have a video in this forum which tells people that they cannot do it.
That in itself might cause someone to decide not to invest in either the echo or the SmartThings system when this forum should be exactly the place where they come to find out that, yes, there is a way to do it.
For example, I myself am quadriparetic and physically have a very difficult time moving the interior turnbolt on my front door. I rely on home automation to be able to do this kind of thing by voice. If the first thing I had discovered was your video, I would’ve been very discouraged and not moved forward with a feature which has turned out to be extremely helpful in my every day life.
I suggest you restrict your general interest videos to your own website if they are going to just cause confusion for people who come to this forum. If you develop some which in fact showcase the true power and features of the SmartThings system, then I’m sure those will be very welcome.
JMO
Anyway, one way to get Echo to unlock A door when the lock is controlled by smart things is to set up a routine that does the unlock, then create a virtual switch that triggers that routine. Now you can have echo turn on that switch.
Another popular alternative is just to use IFTTT. In that case you don’t need a virtual switch at all, you just use the echo service/channel for the If and the SmartThings service/channel for that.
The clunky part is choosing what you want to say. Since it’s a switch, echo expects you to say “on” instead of “unlock.” Some people are fine with saying “Echo, turn on the front door.” But most people don’t like that.
So that’s where you have to start getting creative. 
If you use IFTTT, you can use any phrase you want, but you have to put “trigger” in front of it. So at my house I just say “echo, trigger unlock the front door.”
If you really truly just want to say “Echo, unlock the front door” you can, but you will have to use one of the advanced Echo management smartapps like EchoSistant or AskAlexa which have been developed by this community. They work great, but the set up is pretty complicated. There are lots of people who will help you do that, but it’s just something to be aware of.
You can find both of those advanced options in the quick browse lists in the community – created wiki in the project report section on the “voice” list.
The videos in post one of this thread are plain-vanilla descriptions of the standard features currently provided by Echo. But you can do way more than that if you have SmartThings. This post describes four different ways to have SmartThings enable echo to unlock a lock. ( virtual switch plus routine, IFTTT, EchoSistant , askAlexa) But there are even more than that. Some are easier to set up than others, some offer more choices of verbal phrase, but the point is it can definitely be done. And for some of us, that’s a very important fact. 