Textbox Notes Inside Invoice

Hello,

i buy and installed WooCommerce PDF Invoices & Packing Slips professional and all it works well.

I just need an infos.

My client probably will create some order also by backend side, and need also textarea note to compile and that will be printed inside the invoice, maybe at the bottom of the product or everywhere inside the invoice. So..there is possibility to add this skill in some way. Could be very important.

Thanks to help me.