Do any doctors sign ( tpd total & permanent disability discharge) applications? online?

We surely hope not. To certify a person's disability or non-disability requires a doctor who knows the patient's full history and exam. That means the doctor to do this is either the patient's in-person long-term PCP (primary care provider), or a doctor who specializes in disability in-person exams, or both; but certainly not an online doctor who cannot do an in-person evaluation.

There are strict requirements for such exams and issuance of certificates, they cannot be completed on line. Have your main doc guide you through the process.