Lighroom's exported photo shown differently on iPhone.

This likely is a problem with calibration on your desktop. Most likely a corrupt display color profile. You need to use a hardware calibrator such as a spyder Pro, a colormunki, eye1 etc. these are essential tools. If you don't have any of these, you should set the display profile to sRGB. You are likely on a windows machine if you have this issue and you do this change by going to the monitor properties and deleting the color profile associated with the monitor.

That said, you should first make sure you turn off any of the night shift features on the phone. They shift colors unacceptably and can make your phone' colors look really bad in indoor lighting or late at night.