Inquiry on Licensure by Examination

hello everyone, im a foreign graduate nurse who wants to apply for licensure in the state of texas. one of the requirements stated in the checklist is to register with NCS pearson/vue prior to approval by the board to take the NCLEX-Rn examination. am i not suppose to wait for my application to be eligible before registering to pearson/vue? im really confused, what if i register to pearson/vue and my application is disapproved by the Board. please anybody can enlighten me? thanks.