If you are getting the error message "no pending application" when booking for a driving test exam then it means that your school has not approved the test. Contact your driving school and ask them to approve the test before you book.
If you are getting “you have pending application” error when applying for SMART DL after passing the test then first apply for an interim DL (which costs ksh. 750) and then the option to apply for a Smart DL will appear which you will again need to pay.