How can we create manual bill with negative quantity?

Hi Experts,

I have a requirement, where the user wants to post negative quantity i.e. consumption via manual bill. I tried but SAP doesn't allow posting negative quantity via Manual bill. The situation is for the rectifications happening for the documents/bills which were migrated. We dont have actual billing documents for them but we now want to post rectification bill for those customers via manual bill. Is there a possibility?

Thanks in advance.