While it's possible to use domain credentials to connect to SAP with on-premise installations, most cloud hosting providers integrate the domain credentials into their overall security sandbox and bypass the OUSR table, making them unavailable for verification purposes. This means that if you enter the domain credentials on the MyData tab you may see the following:
In these cases using domain credentials to connect to SAP is unfortunately impossible as the various cloud solutions offer no standardized way to validate domain credentials (if they offer any at all). The only possible workaround is to use SAP user credentials to connect to MyData.
Q) I can't get my direct SAP credentials. The cloud host has only provided me with the domain credentials.
A) The direct SAP user login still exists behind the cloud domain solution although you may need the cloud provider to get it for you if you haven't been provided it automatically.
Q) Can't you validate the user some other way?
A) We wish we could do anything else, but removing the domain information from the database means we simply do not have access to any way we can validate the domain login and tie it to a user in SAP. This means we cannot show the personalized MyData tab as we do not know which user we are talking about. We have started looking into alternatives such as providing an entirely different authentication mechanism through custom fields, but as this will have to be built from scratch it's not a not a simple fix.