How to make track sounds loud (in LUFS), according to streaming platforms requirements?
Hi. Yes, you are right if you are going to distribute or your music through to streaming platforms there are some requirements for audio. Even if you use music for youtube video, is also good to make your audio fit special requirements for audio. Google for this requirements, as it is vary a bit depending on platform.
Answering your question can say that to rise up a loudness of a track you may change and rise the volume level, apply compressions, limiters to each track in the mix individually, then sum up volume will rise as well. If you just have a final mixdown to rise it’s level you can use Peak normalization or the Loudness Normalization. Hope it helps, Good luck!