Yes, you have to pay the visa fee at the Post bank or through Mpesa before scheduling. First, you have to create the account immigrant side, then follow the flow of the account up to payment then prompt you to pay the visa fee. Here it gives you option either cash which you pay it in Postbank or Mpesa. If through cash it will prompt you to print out a paper which you will carry with you to make payment at Postbank (Kenya). Afterwards, will take 1 to 2 days to get updated in your account. Then from there you will see the calendar to schedule appointment.Hope you will get one soon.Be blessed