where do you check to see if engine needs oil. on 2011 Mercedes-Benz E550 4MATIC

I notice only one port for adding oil located at firewall

Asked by for the 2011 Mercedes-Benz E550 4MATIC
If you have the owners manual it will show/tell you how to check the oil.
1 more answer
Possibly through the information display menu.Electronic level sensor , likely , not dipstick. A dipstick would be to low-tech and easy!