Enable or disable the Add button in a master-detail form

[fparedesac]

Hi everyone, this is my first APP using Appsheet, so I appreciate your help with a problem I have.

Part of my App is an invoice with its detail, I have two tables, one of Invoice and the other Invoice_Detail. The two tables are linked to the ID_Invoice column. The invoice can have two states (valid, voided), I control the change of state with an Action and it works correctly.

In the UX section when I save an invoice, it takes me to the detail view and shows me at the bottom an inline form of the invoice detail with the buttons to view and to add new lines.

What I need is that if the status of an invoice is Voided, that the add line button does not show. To do that, in the Add action of the Invoice_Detail I wrote this condition:

LOOKUP([ID_Invoice],“INVOICE”,“ID_Invoice”,“Status”)=“valid”

The problem is that in any state of the invoice it hides the Add button.

Thanks your help!!!