after run 'hello world ' in my sys insted of cesium website , what should i do ?

i follow steps here

the last step after adding a code does not change anything , why ? is it should view the ground vehicle?

this is what run

بتاريخ السبت، 22 ديسمبر، 2018 5:35:18 م UTC+2، كتب Ikhlass Ramadan: