You will find the coupon code on the insert card (box version) or in the email you received following purchase (download version). Activating the coupon automatically downloads and starts the installation setup for the add-on programs.
If VPX is the same as MEP 2021, there is no coupon; you download a Prodad exe file from the link in the MEP main program order email. That link also provides the activation code. You then run the EXE file to install the 4 Mercalli components and on first attempt to use one of them, you will be displayed a slot to insert the activation code.
The order email is needed for the Prodad download link. I don't know how addons work with a boxed version.
Also, the links for the downloadable extras in the email are valid for only 90 days.
As I say, this is for my very recent upgrade to MEP 2021.
I notice you quote part of a serial code, beginning P2. That suggests you are actually using a rather old version of VPX (current serial keys begin P3). So, please tell us the exact version number you have (check under Help>About).
If I am correct about this, it is quite possible the licence for those ProDAD plugins has actually expired since they are often not "for life".
One other thought: has this situation arisen because you have recently reinstalled your version of VPX? If so, it is possible that those plugins were available only for the initial install of the app.
You are absolutely right. I did not scroll down far enough in My Products and got an old VPX serial number. Mine does begin with a P3-.
In the Mercalli Pro effects section, there is an "Unlock" button under "Mercalli v5. When I click on that it asks for an "Activation Code". I think that I used to have access to that. Wasn't that provided as part of the purchase of VPX 12?
I believe that activation code would have been included in the email you received when your purchase of/upgrade to VPX 12 was confirmed by Magix. Do you still have that email?
If not, I think you need to email infoservice@magix.net and ask if they can resend the email (and code(s)) to you. For licensing reasons (of third-party software) they may not be able to do so.