Extra Field On Invoice Template

I am using cs-cart latest and trying to add extra field on the invoice template in the documents section.

My extra field is with

id:40

name:vat

section:Contacts section

Tried:

{{ u.email }}
{{ u.fields.40.vat }}
{{ u.fields.40.value }}
{{ u.fields.40 }}
{{ u.c_fields.40.vat }}

{{ u.c_fields.40.value }}

{{ u.c_fields.40 }}
{{ u.c_fields.40.vat }}
{{ u.c_fields.40 }}

{{ u.c_fields.vat }}{{ u.c_vat }}

{{ u.c_vat.40}}

{{ u.vat }}

{{ u.40 }}

But none worked..

I am using cs-cart latest and trying to add extra field on the invoice template in the documents section.

My extra field is with

id:40

name:vat

section:Contacts section

Tried:

{{ u.email }}
{{ u.fields.40.vat }}
{{ u.fields.40.value }}
{{ u.fields.40 }}
{{ u.c_fields.40.vat }}

{{ u.c_fields.40.value }}

{{ u.c_fields.40 }}
{{ u.c_fields.40.vat }}
{{ u.c_fields.40 }}

{{ u.c_fields.vat }}{{ u.c_vat }}

{{ u.c_vat.40}}

{{ u.vat }}

{{ u.40 }}

VAT:{{u.b_vat}}