For the Digital Nomad track, please refer to the requirements stated in the RTE website. You don't necessarily need to be the owner of the business. You can be a freelancer but get one of your clients to write a letter of employment and provide the ACRA business registration
If you are a remote worker, you should submit a letter of employment or contract with your client stating you work remotely. Not a letter of sponsorship.
Avoid going to Burma (Myanmar) unless you are sure your passport can enter without applying for an e-visa. Their e-visa system has been down since the earthquake on 28 March.