Modify an import file in a new file

Hallo everyone! I’m studying and practicing Synfig tutorials and other tutorials found on youtube. I then tried to create my first simple animation.
I create a character in a file.sifz, I open a new file and import my character.
How to modify or animate an import character into a new file, without changing the original file?
Thank you!

Duplicate the file in the file manager before importing into the Synfig.

Ok, thank you for answering me! It’s a pratical mode to solve the problem.