I set 2 cameras in my Home Assistant. Using motionEye addon, which also have motion detection.
Same thing can be done with iSpy, maybe even better because iSpy have zone motion detection.
Now I want to somehow add this cameras to Alexa.
I'm using HA Cloud (trial) and HA Alexa skill, which discovers all HA stuff, but Alexa don't find cameras from HA ...
I am sorry you are having this problem. Did you already search at the Home Assistant web page for possible discovery modes? I would check on their end if there are settings that you might have to enable in case for Alexa to be able to find your cameras from HA.