BATF considers and 80% lower an unfinished chunk of aluminum. It can ship to your house. (check state and local regs) You can finish the 80% lower on a drill press but you need the jigs to do it.
I just machined 2 on my cnc mill with no fixtures.(just a vise) However each lower was from a different manufacturer so they were not machined identical.
It is not required however for best wear the lower should be sent off to be anodized with a MILA8625 Type III hardcoat which runs From $50-$100+.
Honestly if I did not have a mill I would just have bought a stripped lower with SN or a complete lower vs buying fixtures, whittling it out on the drill press and paying to have it anodized.