TTGO ESP32 Camera: GPIO 33 can't be selected as wake up pin

Hi all. I bought TTGO esp32 camera with PIR sensor for my video doorbell DIY project.
The main idea was to use advantage of deep sleep function. However ESP home says that it is not possible to use PIR sensor GPIO 33 as a wake up pin.
I am not sure whether this some technical or firmware limitation. Could this be changed in future?

thanks in advance.

Kind Regards, Yury.

Exactly as stated in the docs.

However the reason for this is unclear to me. For example this page says wake up is possible in GPIO33

Perhaps @OttoWinter may be able to explain, but if he deosn’t you might want to post an issue on github.

Hardware limitation - the GPIO33 is not an RTC pin, and thus is is not accessible from the hw unit that does deep sleep.

Thank you guys for clarification. I assume that we can close this topic

I have the very greatest respect for your knowledge @OttoWinter, but there are many places on the net which say gpio33 can be used. Am I misinterpreting what I am reading?