Which is the correct way to create bullet points in Markdown — using space+hyphen or tab+hyphen ?

- first level bullet point
 - space+hyphen 
- first level bullet point
    - tab+hyphen 

EDIT: I’m sorry my original post was a bit unclear. I have updated that, could you pls check again?

In Obsidian, I can easily indent a bullet point with tab and Obsidian uses tab indentation by default, is there a way to change that?