Got it. I don’t know if you NEED to have it ask for permission (I do anyways, it only asks once). You need to add a new key to your Entitlements file, then it works.
I’ll leave this here for other people that are googling. It’s unfortunate it’s not as well documented, but having this off by default is the right choice. Asking for permission in apps that don’t need it will get you rejected from the store. It would be nice if there was better integration, but knowing is half the battle… or all the battle…
{PROJECT}/Build/Mac/Resources/Sandbox.Server.entitlements
and
{PROJECT}/Build/Mac/Resources/Sandbox.NoNet.entitlements
<key>com.apple.security.device.camera</key>
<true/>