How can I add a field like "insurance" after shipping in an invoice, like an income. I customized the field with the insurance but when I can't put any amount

Hi there, neybeth.barral, 

Let’s add the insurance amount as an income when creating an invoice.

I appreciate you using the custom field in the Account and Settings in QuickBooks Online (QBO).

Using custom fields for insurance will not add to the total invoice amount in QBO. If you’ve checked the Internal box, it’ll display in QBO. If you’ve checked the Public box, it’ll display both in QBO and printed on the invoice. You can check the InsuranceCustomField.PNG below for your reference.

Since you wanted to tag the insurance amount as income, you can add it as a service item. Here’s how:

1. Go to the Gear icon on the Toolbar.
2. Under Lists, then choose Products and Services.
3. In the Products and Services window, select New.
4. Select the product or service type.
5. Enter the new product or service information and the income account.
6. Click Save and close.

Please check the ServiceItem.PNG to guide you through the last two steps.

Once the insurance service item is created, you can enter a line item under Product/Service column when creating an invoice. Then, surely it’ll add to the the total invoice amount in QBO. For reference, see the InsuranceLineItem.PNG below.

Please let me know if you need anything else while working in QBO. I’ll be around to help you out, neybeth.barral. Have an awesome day!