My iPhone 13 new is heating more while charging

That's normal.

See this support article:--> If your iPhone, iPad, or iPod touch gets too hot or too cold - Apple Support

For your peace of mind, since your iPhone is still covered by warranty, you can make an appointment (*) and have your device inspected at an Apple Store or AASP (Apple Authorized Service Provider) among this list:--> Apple – Location Selector. After checking it out, they'll give you all the available options.

Regards

Giulio

(*) You can do it:

• Online:--> Genius Bar Reservation and Apple Support Options - Apple;
• Contacting a local Apple Store or AASP among the list provided above;
• Using the "Apple Store" app, available and downloadable from AppStore.