Invalid Certificate Windows App - How to fix it?

I compiled an app for windows with cordova. I got the files in the screenshot.

First of all I started the installation file for the certificate. At the end it says that the certificate was installed successfully. If I open the .appx file now and click "install", I get an error, that says (I translated it into English myself, the original language is German, I poste the original text below):

English translation: Either you have to install a new certificate for the app packet or you need a new app packet with trustworthy certificates. To do so, please contact your system administrator or app developer. A certificate chain was processed but ended with a untrustworthy root certificate (0x800B0109).

original text: Entweder Sie müssen ein neues Zertifikat für dieses App-Paket installieren, oder Sie benötigen ein neues App-Paket mit vertrauenswürdigen Zertifikaten. Wenden Sie sich dazu an Ihren Systemadministrator oder App-Entwickler. Eine Zertifikatkette wurde zwar verarbeitet, endete jedoch mit einem nicht vertrauenswürdigen Stammzertifikat (0x800B0109).

What have I done wrong and how can I fix it?

The solution is, to install the certificate on the "local computer". Then choose the second option (where you can choose the directory where it is saved) and choose the Trusted Root Certification directory.