How to export a Document Library as model from one site to another

Hello everyone,

I've created a Document repository, add some document set and after saved as  template in a site /A.

So in site /A i can take it from apps.

Now i want export this "app" in a new site /B, so in it i can take from the app, and have a completed document repositori with document set.

How can "export" the app from one site to the other ?

Thanks in advance

Antonio