Since moving overseas 15 years ago, I tried numerous times and it simply is not possible. All the forms require a U.S. mailing address to register. Same for online access to your Social Security account.
There are an estimated 10 million Americans living overseas. Taken together, we are the equivalent of the 11th largest state. All of us completely blind to what is happening with our credit record and Social Security account.
At this point I think the only way this gets fixed is massive fraud/exploitation by organized crime, so these organizations finally address the problem.