Hello Tesfai20141
Thank you for reaching out to us here at the Community!
If you have an invoice and you wish to apply a credit note to it.The first thing to do would be to check in the settings if you have auto apply credit note turned on as if so it will just apply a credit note to the oldest invoice.
To check this go to the cog in the top right>account and settings>advanced>automation>automatically apply credit notes>toggle off>save
Once this is done you can create the credit note using the + symbol and credit note and then go to receive payment on the invoice and the credit note will be there for you tick
Any questions at all on this just reply back to this post on the Community
Thanks
Emma
