Yes, there are a couple of ways of doing this, one online, one on the device.
You can go to the https://mydrive.tomtom.com
site, and enter coordinate data there, and mark it as a My Place, then allow MyDrive to send it to your device. Note that MyDrive only allows coordinate entry in dd.ddddd dd.ddddd format (decimal degrees). You cannot use decimal minutes, or degrees/minutes/seconds.
You can also Search on your device, changing the usual "Whole map" in the upper righthand corner to "Latitude Longitude", enter coordinates there (it allows all three of the typical coordinate formats), and having shown that location on the map, hit the little 4 dots in circle icon, and "Add to My Places".