H1B - How to Recapture my remaining H1b duration(6 Years)

Need your valuable feedback.

Company A sponsored a H1B and i have worked in USA for 4 years between 2014 and 2019. In 2018, i have filed an extension and it went RFE and i responded RFE and used 240 days grace period until Jan 2019… My extension denied and i came back to India within a week time… I have my PERM and I-140 approved … Now I am no more with Company A… How to recapture my unused 2 years H1B … where and how to start the recapture process?.. Please guide me on this.

Thank you.

There is no separate process but it is part of the H1B petition (I-129) whenever the H1B employer files it to hire you.