Hello student no matter if you're enrolled online or offline but now it's mandatory to submit the assignment online only offline assignment will not be accepted from 12th April 2020. So yes you can submit your assignments online on the official website of IGNOU.

For more details refer to the link mentioned below - https://hpuniv.in/ignou-online-assignment-submission-yadot/#:~:text=IGNOU%20has%20extended%20the%20assignment,following%20the%20process%20given%20below.&text=Update%20on%2012th%20April%202020,be%20accepted%20from%20now%20on.

Feel free to comment if you've any doubt

Good luck