Hook up propane fire pit to house hook up
What you see there is a male &quot;flare&quot; fitting, so you'll need a female flare to mate with  it.
It sounds like at the fire pit you'll need a male tank adapter.
I'm not sure you'll find that as an assembly, so you'll want to look into how to make and test gas line connections. You need either gas-tolerant PTFE thread tape or thread compound paste.