iPhone 15 not charging

Can you try to charge it wirelessly?

You should visit an Authorized Apple Service Provider next to your place and let them check your device, which would be the fasted way to a diagnose and solution.

Apple - Find Locations

Or contact the official Apple Support about that, since your iPhone is still under warranty.

Contact Apple for support and service - Apple Support

These ar brand new devices, I see lots of this battery-charging issues. Until now no solution with the exception of visiting a apple service provider or (in my case) performing a cold boot before the battery ran out.

I contacted Apple support (with my wife's phone 😳) and the answer was: there can always be an issue with an iPhone, suggesting just to accept it.. or visit an apple service provider. To do what?