IAS Myob upload

Hi All

I was wanting to prepare the monthly IAS in Myob but unfortunately this error message came up:

We can’t retrieve your activity statements from the ATO.

You are not authorised to submit this lodgment on behalf of the client. If you are a tax practitioner, ensure your registered agent number is used in the transmission and try again. If you are a business sending on behalf of another business, get an Authorisation administrator to ensure there is a business appointment in Access Manager and give your credential access if required.
If you contact the ATO, quote this code: CMN.ATO.AUTH.008

We do not use a tax agent as we are not GST registered and only the monthly IAS gets submitted through the Myob Portal.

What has changed and why is our access blocked now?

Any advice is greatly appreciated.