This is the first update for the standard Moto E5 Play from the Big Red, coming in bearing software version ODPS27.91-167-1 and installs a new Android security patch for December 2018.
A similar security update is also rolling out to the prepaid variant as software version ODPS27.91-121-4, but unlike the standard model, the prepaid variant is receiving the fourth software update since its launch on the giant carrier.
Both devices are receiving the updates over the air, meaning it will take some time, probably a few days, before all Moto E5 Play units get the download notification, so your patience will be paramount here.
You have the option to wait or try forcing the update via the settings menu, but whatever option you pick, be sure to connect to a stable Wi-Fi network. Also, ensure you have enough battery juice (at least 50%) or connect the device to a charger near you.