Require help for types in header files

I am new to PlatformIO. I created a project in VSCODE that uses Ardiono and ESP32 frameworks and taergt is ESP32.
I am having trouble with the compiler not finding types using in header files and must be missing a #include for types?

The unit8_t and unit16_t all have the red squiggly lines and error states they are undefined.


#ifndef crc16_h

#define crc16_h

uint8_t valid_packet(uint16_t,uint8_t*);

uint16_t get_crc_16(uint8_t,uint8_t*);


You’re using types from stdint.h, but where’s #include <stdint.h> in the code?