You can use the Retro Claim option for that, for bookings in the past 90 days. All you need is the PNR number of the journey irrespective of where it was booked.It does say you get bluechips also for OTA and travel agent bookings as well. Do bookings via MMT or smartbuy also get you bluechips then? How does it figure out your indigo account for crediting bluechips in such a case?
I did the same and it worked for me. Check it out at this link: https://www.goindigo.in/loyalty/dashboard/retro-claim.html