rename error in flink sql

[??????]

I'm learning "select"from
official document





my code is:
https://paste.ubuntu.com/p/yVYhZqMNq7/


the error I got is:
&nbsp;total is not found in PojoType<Order, fields = [amount: Integer, product: 
String, user: Long]&gt;


It's strange that the rename name should be found in pojo.


Could anyone help me?
thanks for your help