Fixed binary is not serializable error

api/models.py

@@ -10,7 +10,12 @@ class User(db.Model):
     admin = db.Column('admin', db.Boolean(), server_default='0')
 
     def as_dict(self):
-        return {c.name: getattr(self, c.name) for c in self.__table__.columns}
+        return {
+            "email": self.email,
+            "username": self.username,
+            "telegram_user_id": self.telegram_user_id,
+            "admin": self.admin
+        }
 
 
 class Transaction(db.Model):