Formula Field/Campo de Fórmula

Formula Field/Campo de Fórmula

Hello everyone,

I have a purchase requisition form in which each department submits a request, and the request is automatically routed to the person responsible for that department.

In this form, I have several fields with the following link names:
Quantidade1, Valor_Unit_rio, Frete_Item1, and Valor_total1.

The field Valor_total1 is a formula field calculated as follows:

input.Quantidade1 * input.Valor_Unit_rio + input.Frete_Item1

All these fields are related to each individual item added to the form.

Now, I have another formula field that must sum all the added items, representing the total value of the entire requisition.
The link name of this formula field is Valor_Total_Requisicao3.

This field needs to receive, in its formula, the total sum of all item values.

As shown in the image, the initially mentioned fields are located in the form section called “Itens1”, and the section below is dedicated to the total requisition value, where the formula field Valor_Total_Requisicao3 is located.
The name of this section is “Valor_total”.

Could someone help me with the correct syntax, considering that these are the fields and sections available in the form?