Download my minecraft World.

Good Morning,
I have a problem with downloading my minecraft world. I made a world with crazy builds and saved it in aplication storage. Now i want to download this world so i can never loose it, even if i change the device to newer one. I have wathed couple of tutorial but it seems impossible to download it from app. I have also searched my phone files but i didn't find my world there.   Is there a chance you could help me with that? The world means everything for me. Thanks a lot!