Penalty u/s 271(1) (b)

Simply narrating all facts request to assessing officer to drop the penalty proceedings.

how to do this in e proceedings as penalty already issued.

As you said in your previous post that penalty u/s 271(1)(b) has been initiated means you have been given an opportunity of being heard as why penalty u/s 271(1)(b) should not be imposed. you have to respond to the show cause notice through e-proceedings from your e-filing portal. If you want submit documents in support of your reply you may also upload with your reply.