My iphone 11 plus is always hot

What does your Maximum Capacity show at Settings > Battery > Battery Health and does it say it’s at Peak Performance or another message?

Is your iOS up to date?

Are all apps up to date?

How much Available Storage does the phone have remaining?

As for the heat, that is typically normal. The phone is designed to let heat from use, especially intensive apps and processes, escape thru the case. See https://support.apple.com/en-us/HT201678