Adding days in date using modified java script

I have a list of 10 dates in excel and i want to add 3,4,6 days respectively in them.

eg 01-04-2020 add 3, 04-04-2020 than take output and add 4 in result date to get 08-04-2020

Have you tried to use de calculator step?

Can you please suggest me how to do it using Modified Java script.

Please can you refer to the AE CookBook video -