How do i edit the message in an invoice before i email it? and not the "template"

I appreciate you reaching out to the Community, @KW72 

There's an option to edit an invoice in QuickBooks Online. Let me show you the steps:

1. Go to Account and settings in the gear icon.
2. Select Sales.
3. Click on the pencil icon in the Messages section.
4. From there you can start editing.
5. Click Done.

You may refer to the screenshots below:

Also, you can still edit the email body in the invoice before sending it even though you've already created it.

See the screenshot below:

If you want to learn more about how to set up automatic reminders for your customers, you can check this article: Send invoice reminders automatically or manually in QuickBooks Online.

If you have additional questions or concerns about editing your invoice message or any QBO processes, please let me know. I'd be happy to help you, @KW72 

That does not work.

I have changed the "default" invoice - i have tried to edit the invoice in various "screens/options" 

for my billing - i duplicate invoices (i invoice customers quarterly)...  in the past - editing the context was an option - it is not an option - and im not able to change the default invoice.

I can see that you did everything you could to edit the default email message for your invoice, @KW72. I appreciate you for that.

Occasionally,  the data stored in your browser's cache can cause unexpected behavior with the product. With this, I recommend accessing your QBO account through a private or incognito window to verify if cached data is the cause of the issue. To save time, use these keyboard shortcuts:

• Safari: Command + Shift + N
• Mozilla Firefox: CTRL + Shift + P
• Google Chrome: CTRL + Shift + N
• Microsoft Edge: CTRL + Shift + N

After signing in, please go to the company settings to see if you can change the default message. If it works, return to your regular browser and clear its cache. If not, consider using a different browser to determine if the problem is specific to the one you're currently using.

Once everything's fine and you've emailed the invoice to your customer, learn how to record their payment using this guide: Record invoice payments in QuickBooks Online.

If you have additional questions or concerns about editing the default email message, hit the reply button below. I'll be around to answer them for you.