Thanks for checking in with us. cc_staff.
All third-party applications (non-intuit) will no longer have access to their software. I'd suggest getting in touch with the ETO Support Team.
They'd be able to provide you with the steps on how to communicate and create invoices using their program.
In case you need help with creating and paying invoices in QuickBooks Online, we can refer to the articles below:
Create invoices in QuickBooks Online.
Record invoice payments in QuickBooks Online.
Please get back to me if there's anything else you need, cc_staff. I'd be more than willing to lend you a helping hand.
