Letter Head not showing up in certain print format when exported to PDF

ERPNext & Frappe Version
ERPNext: v14.31.3 (version-14)
Frappe Framework: v14.41.0 (version-14)

I would like to add my own print format for Sales Invoice. The problem is, when I use the print builder beta, the Item table not showing up in the print builder beta.
When I switched to the current print builder app, the sales invoice item tables shows, but the problem is now the letter head not showing up when I produce the PDF.
I already try to duplicate the “Sales Auditing Voucher” print format that contains both the Sales Invoice Item and the Letter head when exported to PDF, but in the duplicated print format, the letter head still not printed when exported to PDF.

For the server-side solution, I already installed the wkhtmltopdf version 0.12.6 as recommended for letterhead in pdf problem, I also already add the “host_name” : “{url}” in the site_config.json in the server.

Any pointer or solution to my problem?