Rename photos files name by adding yyyymmdd

Photos files name are generated by camera like
IMG-4001.JPG
IMG-4002.JPG
...
IMG-4099.JPG

How rename them to add today's date format yyyymmdd like below (Tomorow will add 20200914, so on)
20200913-4001.JPG
20200913-4002.JPG
...
20200913-4099.JPG

Add:<Year><Month><Day>-
At index: 1

Reply to #2:
How to remove "IMG" from original file name?
From "IMG-4001.JPG" to 20200913-4001.jpg"?

Reply to #3:
Try reading the User Guide!