ESP32 bootloader_random_enable() - undefined reference

The ESP32 hardware RNG requires WiFi|BT (RF) to generate true hardware RNG.
In lieu of RF being enabled PRNG is possible and should first call
bootloader_random_enable() according to

esp-idf/bootloader_random.h at 1ca2afd982230e4cbf021c58137f3141c1870572 · espressif/esp-idf (

I have included
#include "bootloader_random.h"

I have noticed the file exists at:


However, when compiling for ESP32 boards I get the "undefined reference" error on the function call bootloader_random_enable()

I don't get an error message from the #include, am I missing some path info?