Import Error: 'User' object has no attribute 'set_password'

Traceback:
Traceback (most recent call last):
  File "/var/task/api/app.py", line 9, in 
    app = create_app()
          ^^^^^^^^^^^^
  File "/var/task/app/__init__.py", line 102, in create_app
    demo_user.set_password('demo123')
    ^^^^^^^^^^^^^^^^^^^^^^
AttributeError: 'User' object has no attribute 'set_password'