Hi Joy-Threaker,
Thank you for reaching out on this and welcome to our community!
So that we can better assist you with this, do you mind if I ask what you are trying to achieve? Are you looking to apply an adjustment note to one of the invoices you sent to your customer? Assuming that's the case, here is an article from our community that might be useful for you:
Create and apply adjustment notes or delayed credits in QuickBooks Online
Thank you and please let us know if you require any additional assistance.
