How to deploy Admin block extension to Store

[nhtbao101]

I'm following the docs of Admin block extension to custom the UI of Admin customer detail, I can preview this app but can't deploy this app to my store.
When I run the deploy command:

npm run deploy

I got an error: 

extensions.targeting: Block extension is in developer preview and cannot be deployed to production stores.

I checked the docs and it says: "Admin blocks are in developer preview and can't be deployed to production versions of your app."
So I have a confused: If I cannot deploy this app to my store, how can I add and customize the UI of admin in production environment. If cannot, is another way to customize the Admin UI?

Any suggestions or recommendation?
Thanks in advance.

[ssspai]

Facing the same problem. How did you figure it out?

[Oldfire]

Depends on what you are trying to achieve here really. The standard way of adding functionality to the admin area is through admin actions, instead of admin blocks, at least until the latter is released.