You can create a SO with the negative quantity to start a return process.

- Once SO is validated, a receipt is generated (instead of delivery)

- Once generate invoice from this SO, A Credit Note is created (instead of Invoice)  

Hi Rizal,

Kindly check this custom-built "Return Merchandize Authorization" App 

https://apps.odoo.com/apps/modules/17.0/ewall_rma 

Hope this helps & answers your question 

Hi jaideep, thanks for your answer

I have done the return transfer, but how could i create a delivery order and associated/generate it with the sales order?

Hello, head over to the purchase order, then delivery and then clikck the Return button,

you will get a popup screen where you can input the number of returned items and to which stock location to return them. Like so:\

The above operation will take care of the stock.

In accounting, DO NOT FORGET to create a Credit Note for your customer for the value of the items he returned.

Process ‘return’ on the validated customer return operation (the receipt operation)

OR

You could create a new delivery order for the associated sales order.