CAN'T Download into STM32

I can’t upload code to my developer board ,following is my setup in .ini file
IDE: VScode

platform = ststm32
framework = stm32cube
board = genericSTM32F103ZE
upload_speed = 115200
upload_port = COM4
upload_protocol =serial

You also put the chip into UART bootloader mode, yes? 6_Programming with UART · palhartinger/HowTo-STM32F103C8T6 Wiki · GitHub? Does it work with the official STM32 tool? FLASHER-STM32 - STM32 Flash loader demonstrator (UM0462) (replaced by STM32CubeProgrammer) - STMicroelectronics

Thanks for your reply,
Yes,I have put chip into UART bootloder mode ,and I upload .hex file into chip success with other tool, but it is not work on "PlatformlO uplode mode ", also you can tell me how to generate .hex by PlatformlO

Auto-detected: COM4
Uploading .pioenvs\genericSTM32F103ZE\firmware.bin
stm32flash 0.4Failed to init device.

There is error information

Which other tool exactly?

A ISP upload tool exactly

Try to use upload_protocol = stlink instead of serial. This worked for me