Display customer linked custom fields in Sales order and Tax Invoice

How to Include Custom information (from Custom Fields) of Customer (like: Contact Person, Mobile Number, etc) in a Sales order, Tax Invoice, etc.

I have added "Contact Person: and “Mobile No” as Custom fields to Customer; and want the same info should be printed below the Customer Name and address automatically when we select a customer in a New Invoice or Sales Order, the information. Please help.

Welcome to the forum @Peekay

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