Install button greyed out, installation not possible

[Andi Saitenhieb]

Hello,
this I my first buy from Melda. I have been using Cubase for 20 years and bought hundreds of VST FX and VST instruments, but I don't understand the strange activation process from Melda:
- First in the MPluginManager under settings the options to choose the Plugin Installation Type and Path are greyed out. (I only need VST3.)
- The licenses are activated (at least the MPluginManager tells me so), but the INSTALL button is greyed out although I have selected the plugins I bought.

What is going wrong here?

Thank you for your help,
Andi

PS
On the website there is no way to support the contact, just a link to the documentation and this forum. That should have made me suspicious in the first place ...
Or did I miss how to contact support directly?

[FatGuy]

Here you have the contact page

https://www.meldaproduction.com/about/contact