Do I need seperate mautic installation for each of my websites?

Hello,

I only learned about mautic a few days ago and still going through the documentation. I am really fascinated by its abilities but also a little confused.

At first I thought I could manage the campaigns for all my websites from 1 mautic installation so I created a category for each one with designated assets and templates. But then I realised there is only a single point I can add google analytics and facebook pixel, the configuration, meaning I can only track 1 website. Same goes for OneSignal notifications, where although OneSignal allows me to create multiple apps, I can only intergrate it once to mautic.

Is there something I’m missing about this? A workaround? Or I just need another mautic installation for each of my domains? That would be a bummer though as most of the contacts are shared between my websites.