The way you configure your setting depends on the type of lobby you want.
Chaotic Lobby? Enable a lot of neutral and neutral killing roles.
Casual lobby? Enable a lot of crewmate roles, with 1-2 neutrals and neutral killing.
It depends on what you want for your lobby, and only you can decide that.
Minimum/Maximum Neutral/Neutral Killing
settings in your Lotus Settings, otherwise none will spawn at all.