Multisite – newly created sites (separate domain) are not showing wordpress

I don’t know where else to turn…I’ve followed every guide I can find on this, but I can’t seem to get wordpress actually working on my new site.

When I visit site2.com, I just get the “index of /” page instead of seeing anything wordpress related. If I switch the URL back to site1.com/site2 I can see it works as it should within wordpress, but how can I actually get site2.com to show wordpress?

Do I need wordpress installed on site2.com separately first or do I need to update the domain itself in cPanel to point to site1.com/site2?