Furnishing tax return after receiving notice u/s 148

I recently received a notice to furnish my IT returns u/s 148 for income escaping assessment AY 2018-19. The notice is valid because I had made some money trading in cryptocurrency and did not pay tax on that. Now that I have received this notice, I wish to disclose this income and pay tax on that. But I am unable to figure out HOW to file the ITR online because there is no option to refile return under that year on the portal. Should I prepare the return using some software outside and simply upload the PDF under e-proceedings?!! If I go under "File Income Tax return" option and choose the relevant AY, there is no option showing for me to file under section 148. It only shows "92CD modified return" and after "condonation of delay" under 119. Everyone advises file revised return but HOW and WHERE?