How to create a temporary file and work with it in Python?

Question

Python

Hello. I am taking a course on Coursera, there is a task to create a temporary storage for storing data in json format. I wrote a script, everything works for me, I upload it to the server - it doesn't work, it gives an error:
Your script ended with an error FileNotFoundError: [Errno 2] No such file or directory: 'storage_path'
I read the documentation on the tempfile module, I didn't understand.
I create a file like this:

storage_path = os.path.join(tempfile.gettempdir(), 'storage.data')

storage_path file is created
Then I open it:

with open(storage_path, mode='w', encoding='utf8') as file:

and then I write, read, etc.
But it doesn't work on the server. Tell me what I'm doing wrong.
sandbox code