Update the notes

models/invoice.py

@@ -11,7 +11,7 @@ class Invoice(Base):
     
     # User selected date (defaults to now)
     date = Column(DateTime, default=datetime.utcnow)
-    
+    invoice_no = Column(String, nullable=True)
     doctor_name = Column(String)
     clinic_name = Column(String)
     patient_name = Column(String)