All the newer shape vehicles require AdBlue as part of their running operations.
AdBlue is stored in the LockUp in clear plastic 10L bottles.

Next to the Diesel Fuel Cap you will find the AdBlue Cap
Just unscrew the cap as normal, attach the filling tube to the AdBlue bottle, and pour it into the tank
Once the AdBlue warning has come on in the bus it will take a full bottle of AdBlue
REMEMBER: If your on a long journey please take a bottle with you and store under the back seats, the warning may come on as soon as you’ve left the yard and then you may not make it there and back
Once the vehicle is out of AdBlue it wont start so you will be stranded until AdBlue is added