There is no intergration guide on there any more
the old guide said this but this call is not in the libary.
/* Call to the function which initializes the BSEC library
* Switch on ultra-low-power mode and subtract a 5 degrees temperature offset */
ret = bsec_iot_init(BSEC_SAMPLE_RATE_ULP, 5.0f, bus_write, bus_read, sleep, state_load,