I am trying to create a custom financial report and need to get the amount_residual from the journal items. According to the very brief explanation in the Odoo documentation all I have to do is reference the code for the report I want like REC for receivables and put .amount_residual after it. No matter what I try I always get a Value Error like it doesn't exist.  The way it is explained is that it is already defined and ready to use like sum.  I've also tried .balance, .credit and .debit all give the same error.  Am I missing something?

ValueError: : "'float' object has no attribute 'amount_residual'"

here is a screenshot of my formula..

and this is the screenshot for my formula for INV