An iPhone 13 Pro battery life is advertised as "Up to 22 hours video playback", however, this can vary depending on your usage, especially over time. as lithium batteries degrade over time, this is why your battery might not last as long now as when you originally purchased your device.
If you go into Battery > Battery Health you will see a percentage that shows how your battery is doing. Apple estimates this figure should reach around 80% after two years.
You can find out more information about battery, charging and optimising your battery to get the most out of it here
That being said, your battery life does not appear to be lasting as long as it should, especially as this is a new device. I would firstly advise to take a look at the resource above for help and if problems persist, please let me know.