I cannot change the text in the email body in my invoice. I used to be able to do that

Good day, @lszumb. I'm here to help. 

I'm here to assist you with changing the text in the email body of your invoices in QuickBooks Online's (QBO) new invoice layout. 

You can individually change the text at the time after creating an invoice by selecting Review and send. I've added screenshots for visual reference. 

However, if you need to update the default text in the email body of all the invoices that you'll send, you can achieve this from the Accounts and settings page. Here's how: 

1. Go to the Gear icon. 
2. Select Accounts and settings. 
3. Choose the Sales tab. 
4. Scroll down and click on the Messages section.
5. Update the Email subject line and Email message boxes. 
6. Hit Save. Then, Done. 
     

After this, let me add this article on receiving customer payments as a future guide: Record invoice payments in QuickBooks Online. 

We'll be here in the Community to assist you in QBO's transition from the old to the new invoice experience. We'll do our best to help. Take care.