It is simple to pay with phone. Please check these 6 step picture example or instead check this TUTORIAL VIDEO.

      
                                          (1)                                                                                               (2)
                                                                            Check this Video Demo


      
                                          (3)                                                                                               (4)
                                                                            Check this Video Demo


      
                                          (5)                                                                                               (6)