I bought Magix Music Maker 2020 premium one year ago and now I'm trying to insert a vst plugin and it doesn't work. I've read some similar problems and I think I didn't use a code that I should. I think my version is not premium and I don't find the code in my emails (I deleted my emails recently) what should I do?
Always keep your activation codes somewhere safe. You can try logging in to your user account on the Magix.com site, going to My Products and you'll probably find your activation code there, assuming that you registered.
Once you enter your activation code, some stuff will be automatically installed, the rest will be under the Download button that will show up at the upper right of the screen. Make sure that you are logged in to the Store. Download and install everything. For some items, it is a 2-step process.
So it appears you didn't register your purchase when you first bought the program. In which case the only suggestion I can make is to use this link and contact the Sales team and explain your problem. They may well ask for detailed confirmation of your original purchase.
Also, in the present coronavirus situation throughout Europe, any reply may take quite some time to arrive!