How do you make or get your coffee water?

Using the right water for coffee was one of the best tips I learned from multiple sources in order to improve coffee at home. I live in a place in Italy with extremely hard water, so I have a cleaning filter installed that still leaves a series of minerals. Water is good to drink but not to brew coffee.

The solution I’m using now is bottled water, which works really well except for the fact that buying and wasting plastic isn’t ideal at all

Is there any way to obtain good quality water without having a ton of plastic in my bin? I mean I could buy mineral pills or something but still I’d need first to get demineralised water somehow, most likely bottled. So I don’t know really