1- How I can add the invoice number to the template? so far not found a way to do this, and I can just add the order number.
Please go to this page: http://demo.cart-pow...8&template_id=4
Find "Order data" section in the right part of the page. Find order id field in this section. Did it help?
2- How can I restore the original template if I disable the addon?
What do you mean restore? If you disable add-on you get original template. If you enable it later, you will be able to use configured before templates. Does it make sense?
Thank you.