Hi keeran,
unfortunately Switzerland is not officially supported yet. See FAQ: Why am I not seeing Brave Ads? for a list of supported countries.
Neither have I looked into the source code how Brave gets the location info nor did I try to fake it as I live in a supported country. But most modern Browsers use the HTML5 Geolocation AP.
So you could try changing the info in the developer tools of Brave.
In your dev tools:
And then you will see the possibility to change your location.
But as I said, never tried it, no guarantee!