Print Format sales invoice

Hi to all,
i 'm trying to create a custom print format for my sales invoice.
I have some difficult to insert the some informations contains in the client billing adddress (phone, address,…), and some information contained in the client fileds like tax id.
How i can llink these informations?

I try to use:
{{ doc.customer.FIELD }}

but it’s not works.

Anyone can help me?

Regards
Alessandro

{% if frappe.db.get_value(“Address”, doc.customer_address, “address_line1”)-%}

{{ frappe.db.get_value(“Address”, doc.customer_address, “address_line1”)}}
{%- endif %}

{% if frappe.db.get_value(“Address”, doc.customer_address, “pincode”)-%}

{{ frappe.db.get_value(“Address”, doc.customer_address, “pincode”)}}
{%- endif %}

if u want to get pincode for the customer_address for example you click on the customer name you see it will take you to adress doctype …
so i use a frappe.db.get_value ( doctype name , “Ahmad Ragheb address” , field name i want form this doctype )

i use a check with if ,
{% if frappe.db.get_value(“Address”, doc.customer_address, “address_line1”)-%}
{%- endif %}

so if there is no value it wont show it .