@NuT_CrAcKeR The following advice is just from my experience as a user. You can also ask support at infoservice@magix.net, but they are currently very slow when it comes to responding to user requests.

If your music is made completely by yourself, yes, there is no problem uploading it.

If you use audio loops, it depends. Magix Soundpool loops are usually available for non-commercial usage or commercial usage (more expensive). If your channel isn't monetized it's fine to upload the music. If your channel is monetized, you need a commercial license for each Soundpool you want to use in your music. If you have a Loops Unlimited subscription, then the included audio loops are only for non-commercial usage.

I think if you bought Music Maker Ultimate, then the included (only the included) Soundpool loops can be used commercially without any additional license. Just to be sure, please read the be EULA in case something changed.

If you use audio loops and samples from other vendors, there might be different licenses. Therefore please always check them thoroughly.

The next problem you can encounter is that your videos on YouTube might get copyright claimed by third parties. This usually happens if you use the same audio loops as other people who added their music to the YouTube Content ID system. Technically, that's not allowed, but nobody at YouTube verifies that. In such a case you may need to dispute the claim and then maybe even need to appeal the claim if the dispute isn't successful. This can lead to video takedowns and copyright strikes. Be aware, that this problem has nothing to do with Magix. It's just caused by the broken Content ID system on YouTube.