Getting error while creating bash scripting in Lab

Please check the steps in the attached gif

mkdir countries
cd countries

mkdir USA India UK

echo "Washington, D.C" > USA/capital.txt
echo "London" > UK/capital.txt
echo "New Delhi" > India/capital.txt


Ok, I understand but If I run mkdir -p /home/bob/countries/{USA,UK,India}
it should run as well, right?

yes, it should run as well.

but it was not running, giving an error.