I am not able to cast from my Samsung Galaxy 7 android 8 android tablet. I go to wifi settings > WIFI direct > Nebula-1D7DF2 and can connect but within few seconds it disconnect.
You need miracast device in order to cast to it from your phone or tablet.
I see so it varies from ANdroid device to device and not a standard android feature?
I had another old unbranded android 7 tablet and that works just fine but not my samsung galaxy s7