Hello im getting this error can you help me with it

C:\Users\HP\Desktop\Chipling-AI-main>python app.py
Traceback (most recent call last):
File "C:\Users\HP\Desktop\Chipling-AI-main\app.py", line 21, in
db = firebase.database()
^^^^^^^^^^^^^^^^^^^
File "C:\Python311\Lib\site-packages\pyrebase\pyrebase.py", line 67, in database
return Database(self.credentials, self.api_key, self.database_url, self.requests)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "C:\Python311\Lib\site-packages\pyrebase\pyrebase.py", line 200, in init
if not database_url.endswith('/'):
^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'NoneType' object has no attribute 'endswith'

I have the env fine created named app.env im still getting the error though can you pls help