You can access the custom field editor in the Custom Fields section of Jetpack CRM Settings, where you’ll see a page like this:
From this screen you can add or update any number of custom fields to contacts, companies, quotes, invoices, transactions, and addresses. Note that adding fields to the “Address” section adds them to anywhere you see Addresses in Jetpack CRM.
When creating a field, you’ll provide a field name, a field type, and (depending on the field type) either an optional placeholder or some comma-delimited options:
Creating a custom file upload box
As with creating any custom field, you can add a custom file upload box in Jetpack CRM > Settings > Custom Fields:
That will create a Files tab/view of uploaded files on your View Contact page:
Note: the only way to add additional files to a contact is via the Edit Contact page.
What field name does my custom field use?
As per the page for all contact field names, Contact Custom Fields get a field key once they’re saved. You can see these keys under the custom field name in a teal-coloured label.