What documents are required for Hainan visa on arrival for Australian citizen?

Thanks for all this information.

I want to ask if there is any additional documentation that is needed to apply for the Hainan visa on arrival. I assume you need to bring some passport photos but do you need any invitation letter as a tourist? Also if I wanted to apply for a 3 month visa on arrival to study in Haikou, would I need an invitation letter for that? Is there any official website with this information, even its a government website in Chinese I can try to read it anyway.

Thanks