Workflow and Invoice have a miss information information in a new relationships

Hi, I need your advice for a easy action, I want to do a multiply Quantity by unit value (without tax), to do that I follow this steps:

  • I add a new field in invoice module (studio).
  • I created a new relationships in invoice between Invoice and Line Items using one to one and one to many.
  • At the end a create a new workflow for invoices, in “Actions” using “calculate fields” I create a new formula {multiply({R0};{R1})}

Problem is both fields are empty, I mean, Quantity and Line Item. So I do something wrong?

I really apreciated your advice.

Brgds

My environment is:
Suitecrm Version 7.10.33
Xampp, windows 10 pro
PHP 7.4.27
Apache 2.4.52 Win64

Can anyone help me, with Invoice Module for work flow… PLS