Demand in intimation 143(1)

The return has been e-filed. by mistake self assessment tax paid has not been filled in the ITR.

Now, intimation 143(1) shows demand payable by the assessee.

Actually, it was paid on the date of filing the return itself.

If it is a manual filing, a letter along with challan copy shall be given the IT office.

As it is e-filing, where & how to reply???