Little off topic, what would it take to take a stand up gun case and make it alexa powered- unlocking and opening closing of door?
Most gun safes these days have a built in lock, and whether or not that can be made smart depends entirely on the brand and model of the gun safe. Some can, but most can’t.
if it doesn’t have a built-in lock, then It would be the same as making any cabinet smart. You just add a lock that smartthings can control and then add Alexa to it. ( i’m not saying this is a good idea, I’m just saying that you can. 
) there are several existing forum threads on making cabinets smart. Here’s a recent one:
Smart Drawer Locks - Help Needed!
All of that said, though, it should be noted that some homeowners associations, some townships, some insurance policies, and some specific court orders including custody agreements may have details about gunsafes with regard to keeping children safe, and I’m not sure that any Alexa-operated method would meet those requirements. So that’s just something you would have to look into.
BTW, here’s a custom built one which is just a cabinet with actuators:
It’s very cool in a John Wick sort of way. But again, not really childsafe.
(Warning: this video may activate nearby echo devices if they use the wake word “ALEXA.“)
Do you know where to buy this gun cabinet or what it’s called?
As I mentioned, it was custom built by the people who did the video. There are some commercially available safes with Alexa control, but they don’t have the moving shelf features as far as I know.
https://www.amazon.com/FORFEND-Control-Detection-Attempt-Predrilled/dp/B0C8F9BRFP?th=1
.
https://www.amazon.com/Eufy-Security-Wi-Fi-Smart-Safe/dp/B09PH8SZ7B/
Try searching for “WiFi safe” to find some options.
If you’re looking for a way to integrate voice control while keeping security in check, a good approach is using a smart plug for power control instead of direct unlocking. That way, you can prevent accidental voice commands from opening your Home Safe while still having automation options. Adding a sensor inside can also give you peace of mind by letting you know if it’s been opened unexpectedly.