Cancel Invoices


Can someone please tell me where I can add a code, if I want to have my invoices have a cancel option like the quotes.


Should the invoices stay available and only be marked as cancelled or can they be deleted?

Stay available and only marked as cancelled but no option to delete.

This is not easy to implement, you could only try to copy the code from the quote modules

Where can I find this module pleaseā€¦