Mostrar CIF cliente en Factura impresa // Show customer CIF on printed invoice

Hola, Necesito que aparezca en DNI o CIF del cliente en la factura impresa.
Tengo incorporado el dato utilizando el código que aparece en este enlace:
https://ayudawp.com/como-anadir-el-cifnif-en-woocommerce/
?Cómo puedo conseguirlo?
Gracias.

Hi, I need it to appear on the client’s DNI or CIF on the printed invoice.
I have incorporated the data using the code that appears in this link:
https://ayudawp.com/como-anadir-el-cifnif-en-woocommerce/

How can I get it?
Thank you.

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