Please let us know, are you using any 3rd party plugin that added information to the Woocommerce order? If yes, then you need to make it compatible with WooPrintInvoice. Because WooPrintInvoice only supports Woocommerce default order information. Moreover, each 3rd party plugin has its own functions to show their information to the Woocommerce order. Hence, it needs to make it compatible with WooPrintInvoice to print their information.
If you need a customization service based on your needs and requirements then please send a message using our Envato Market (codecanyon) profile contact form to click here https://codecanyon.net/user/themelooks#contact (screenshot as reference https://prnt.sc/10o0iwt ) with your requirements with details to get a quote.
ThemeLooks Support Team