Can't build and flash CRServoF lib to Arduino Pro Mini

Hello guys! I new to PlatformIO, and not so understand how it works. Used to use only Arduino IDE before.

My board is Arduino Pro Mini ATmega328 5V, 16 MHz (board = pro16MHzatmega328)
I have installed external lib

Which i need to convert CRSF protocol from RC receiver to PWM and control servos.

I tried to build and flash default main.cpp, it builds, but not flashes to my board.
I found in platformio.ini some lines, that obviously must be changed for my board.

I tried this:

platform = atmelavr
board = pro16MHzatmega328
framework = arduino
upload_protocol = avr-stub
debug_tool = avr-stub
build_flags_cdc =

# The idea here was to make a CDC version with debugging info
# and an env to build as a HID joystick, but turns out it
# isn't in the core so the feature isn't worth me implementing it
extends = env_common
build_flags = ${env_common.build_flags_cdc}

extends = env_common
build_flags = ${env_common.build_flags_cdc}

extends = env_common
build_flags = ${env_common.build_flags_cdc}

And got many errors like this:

/Users/user/.platformio/packages/framework-arduino-avr/cores/arduino/HardwareSerial.h:143:25: note: previous declaration as 'HardwareSerial Serial'
   extern HardwareSerial Serial;
*** [.pio/build/PURPLEPILL/FrameworkArduino/IPAddress.cpp.o] Error 1

Now the main question is how to change it, what i must type here? Or globally, how to make it build and flash to my board?

Thanks in advance for your attention!