How do I add new fields to invoices for specifying additional information?

To add new fields to your invoice, you need to create custom fields for the Invoices module. Here’s how:

• Go to Settings in the top right corner of the page.
• Select Invoices under Sales.
• Go to the Field Customisation tab and click + New Custom Field in the top right corner of the page.
• Enter the Field Name and select the Data Type.
• Choose Yes for Is Mandatory if you want the custom field to be mandatory. Choose Yes for Show in All PDFs if you want the custom field to be displayed in the PDFs.
• Click Save.