error in running the app 

I got this error when I try to run this app locally for a project 
Error: Problem validating asset fields in app.json. See https://docs.expo.io/
 • Field: icon - field 'icon' should point to .png image but the file at './assets/icon.jpg' has type jpg.
 • Field: splash.image - field 'splash.image' should point to .png image but the file at './assets/icon.jpg' has type jpg. 