This is the answer. Or these: https://www.walmart.com/ip/Mainstays-3-Clearance-White-Basic-Adjustable-Curtain-Rod-28-48/50015121?wl13=3114&selectedSellerId=0

Stupid internet videos do NOT understand the antiquated construction we deal with here. Everyone says to nail the curtain rods to the wall, and that just Does Not Work on hundred year old lathe. Gotta nail to the window frames.