Woocomerce_Emails personalization

Hello

I am trying to configure the emails in Woocomerce Settings. All works except in the email text the personalization. I have used it like this

A) {customer_first_name}

B) Hola {billing_first_name}

C) Hola [customer_first_name]!

D) {{customer.firstname}} 

This is used in the part: HTML template as an example: it takes the order number and date also the oder item all this is displaed except the customer first name. What do I have to do?

 

Nr. [wcj_order_number] [wcj_order_date]

Hola [customer_first_name]! Sé que te interesó mi curso de [wcj_order_items_table columns="|item_name|"]