Hello @Rohan Sharma 

Create instant invoice header and save. After saving the header you will have more information button available. There you can add the info you want

any idea how to add payment ref after invocie created and posted in IFS cloud  

above one is when we created new inv but I already created now need to add payment ref

You can go to customer analysis window, select the invoice and under edit info you will have payment reference. You can edit payment reference here for postedauth invoices

Thanks for the support but unforcunatly I don't have right to udpate the same let me check internally