AttributeError: 'NoneType' object has no attribute 'split'

[masonlai]

AttributeError: 'NoneType' object has no attribute 'split'

Traceback (most recent call last)
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 2463, in call
return self.wsgi_app(environ, start_response)
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 2449, in wsgi_app
response = self.handle_exception(e)
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 1866, in handle_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask_compat.py", line 39, in reraise
raise value
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 2446, in wsgi_app
response = self.full_dispatch_request()
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 1951, in full_dispatch_request
rv = self.handle_user_exception(e)
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 1820, in handle_user_exception
reraise(exc_type, exc_value, tb)
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask_compat.py", line 39, in reraise
raise value
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 1949, in full_dispatch_request
rv = self.dispatch_request()
File "C:\Users\hosumlai.virtualenvs\fyp_backendAPI-w1G8fKVR\lib\site-packages\flask\app.py", line 1935, in dispatch_request
return self.view_functionsrule.endpoint
File "C:\Users\hosumlai\PycharmProjects\fyp_backendAPI\flaskapp\my_app\user\views.py", line 18, in profile
access_token = auth_header.split(" ")[0]
AttributeError: 'NoneType' object has no attribute 'split'