Plus account for WotC modules?

Sorry if this has been answered before. I searched but didn't find anything. I'm wondering if you need a plus account to use the WotC modules (like Curse of Strahd). Cuz there's dynamic lighting and stuff right? I'm just confused. Thanks.

You don't need one to use the module, but you require Plus or higher to take advantage of the Dynamic Lighting in the modules.

Ok, thanks.

I am wondering: what if I buy the module with free account, set it in my game, and then upgrade to plus/pro account: will the dynamic lighting be active automatically? or do I need to create another game and import the module from scratch again?

Games created from the module are completely configured for Dynamic Lighting. The current subscription level of the Game's creator determines if the Dynamic Lighting is active or not. If you start with a Free account and create a Game from the module, then later decide you'd like the Dynamic Lighting, you simple need to bump your subscription up to Plus or higher and the Dynamic Lighting in the Game will become active.