Why no responding in Virtual Com after pushing B2 button with MRSUBG_WakeupRadio_Tx example code? Keil project

[Gwo]

example code : MRSUBG_WakeupRadio_Tx of STM32Cube_FW_WL3_V1.1.0

board : NUCLEO-WL33CC1

compiler : Keil

running the code, at first message below will shown on Virtual Com,

"STM32WL3 LPAWUR - Transmitter example.
Use PUSH Button 2 to send a frame."

but after pushing Button 2 on board, no message is shown on Virtual Com?!