is there a way to add a paid at the top of the invoice
something like this picture
Yes, are you using PDF template or ODT?
Look up this URL : Create a PDF document template - Dolibarr ERP CRM Wiki
Once you get the hang of it, customizing PDF is quite easy. Inserting that PAID image is as easy as one line
$pdf->Image("LINK_TO_LOGO", 10, 5, 60.00);
how can we do this only when the invoice is marked paid?