added return data

app/models/loan.py

@@ -222,6 +222,6 @@ class Loan(db.Model):
             'created_at': self.created_at.isoformat() if self.created_at else None,
             'updated_at': self.updated_at.isoformat() if self.updated_at else None
         }
-    
+
     def __repr__(self):
         return f'<Loan {self.id}>'