pretty much any USB DVD rw will work. They’re dirt cheap:
https://www.google.com/search?q=usb+dvdrw=safari=en=lnms=shop=X=0ahUKEwimuNasg_3bAhXpllQKHZZcC0MQ_AUICigB=1963=1296
Mine at work is a slotloader I scavenged from an old defunct powerbook, put
into an external USB case I picked up for
I am runing Mac OS X 10.13.5 (High Sierra) on a 2015 iMac (m that has no
slots for a CD! Is tis typical for that model,
or is that the current state of the art? It has several (4?) USB ports on back,
so there must be an external drive that can Read and Write, but I don 't know
even what to