How to set a Secret File or set such file inaccessable to others

My space include use of a Google API json file. Because it contains the Google credentials, of course it is not good to make a visible like other files like the app.py.
So, how do I make this file inaccessable to others? Or, is there any place on Huggingface where I can set this Secret File and load it in my app codes?
Thanks for all.
Bests.