Cell Therapy News/Articles, page-5720

From the link you have attached:
SAS applications and notifications can only be submitted by certain registered health practitioners. Individual patients should discuss the suitability of using an 'unapproved' therapeutic good with a health practitioner.
'Unapproved' therapeutic goods have not been evaluated by us for quality, safety, efficacy or performance. Therefore, the prescribing health practitioner must consider the available evidence to support the use of the 'unapproved' product and any potential risks for the individual patient.
The responsibilities of the prescribing health practitioner include adhering to relevant standards of good medical practice and obtaining informed consent. The prescribing health practitioner also accepts responsibility for the use of an 'unapproved' therapeutic good and any associated adverse reactions.

As yet there is no evidence that remestemcel-L is effective for Covid-19. We are waiting for the trial results. Results from small group tests have been promising but are not yet evidence.
Doctors prescribe according to evidence based medicine. This is good medical practice. As yet there is no evidence.
Good luck convincing a doctor to take responsibility for prescribing a drug that has not been proven to be effective.