Hi UserCleanedbyClaires,
Thank you for getting back to us on this and I am sorry that's how you feel.
I tried following AileneA's instructions and I was able to find the customise button on my invoice in my QBSE test file to edit the email message.
I would suggest contacting our QBSE support team for additional assistance if you are still experiencing difficulties in doing so. Here is their contact detail:
https://help.quickbooks.intuit.com/en_AU/contact
Thank you and please let us know if you require any additional assistance.
