How to change price formatting from comma to dot ( , -> . ) - Storefront Frontend

I want to change the price formatting from comma to a dot in the Storefront Frontend.
I didnt find a tutorial or a hint how to do this. Do i have to hook into PHP code to do this?

Thanks for your advice.

It was because the language german / ‚Deutsch‘ we had configure was de-DE not de-CH.

You can find it in Settings > Languages > German and then you have to change country and the language to Switzerland or German, Switzerland.

Now it shows up right.