You can follow the general setup guide at https://crowdcontrol.live/setup for extra help with the Twitch Extension, the Crowd Control Desktop Client and other options.
We suggest using the One Click Setup to install Bizhawk, which is found in the Crowd Control Desktop Client. Bizhawk 2.8 is required.
We support the US version (revision A) of Castlevania. Just point the Crowd Control app at your ROM and you are good to go.
Everdrive N8 Pro support coming soon! Want it sooner? Let us know in discord!