RX660 User Boot Mode | Error: call to undefined function '_r_flash_control'

Hello everyone,
I am working on accessing User Boot mode on the RX660 chip to implement a bootloader program for my project. According to the manufacturer’s documentation, there are 32 kbytes allocated for the User Boot memory, located at the address range (0xFF7F8000 - 0xFF7FFFFF). I have modified the linker file to match this memory area.

After that, I added the r_flash_rx (FIT Module) components and built the program, but I encountered the following error:
   error: call to undefined function '_r_flash_control'

IDE : e2Studio 

Compiler : GCC

Debugger : E2 lite

Does anyone know the cause of this issue? I would greatly appreciate it if someone could help me resolve this problem!

With my sincerest gratitude!