As it currently stands, Staff Assistant basically doesn’t exist. The equivalent role we have right now is just trial Moderator, if you make a Moderator application and it’s accepted you’ll be under review for some period of time, usually a month or more, to make sure you understand the banning process and everything while also continuing to uphold good community standards. If you wanted to apply, you can do so here:
Stuff that comes after is generally slow, it might be a few months or several depending on the quality of your player reports and especially your behavior, but if you’re willing to commit the time then you can get accepted.