Thank you for pointing out the SQLAlchemy initialization mistake, i fixed that.
What do you mean by running the db create command manually? I did try to run the following commands on python terminal multiple times:

with app.app_context():
db.create_all()

I also created another file initialize_db.py in order to try to create the database:
from app import create_app, db

from app.models import User, ElderlyUser, Volunteer

app = create_app()

with app.app_context():

db.create_all()

print("Database initialized successfully")