I've checked Honda and Insight forums and have continued to look for solutions, but I can't find anything that would allow me to plug a CD player into the car's USB port and play CDs. I did find an older FM transmitter car adapter with an auxiliary port that will send music to the radio, so...
I just bought an external DVD drive, an LG SP80NB80, to play music CDs via a USB port in my 2022 Honda Insight head unit (which has two USB ports but lacks both a CD player and a 3.5 mm auxiliary port).
I bought it because the LG SP80NB80 is known to play CDs on a 2017 Honda CRV, but...