Update models.py

models.py

@@ -11,6 +11,7 @@ class User(Base):
 
     id = Column(Integer, primary_key=True, index=True)
     email = Column(String, unique=True, index=True)
+    username = Column(String, unique=True, index=True, nullable=True)
     hashed_password = Column(String)
     is_verified = Column(Boolean, default=False)
     credits = Column(Integer, default=10000)