There are no ranks here.
If you bought the game (called premium) then it unlocks with your itch.io email info and itch button. It is not the same as chunin supporter which has early access and like patreon style updates.
You still need to go to the website or discord to get the latest version though. Itch.io version will never be updated until the public version is 'finalized' and stable/bugfree--ish.