I have already filed my taxed for the 2019 year and it did not register my 1098 form from my school. Can I go back and update that after it has been accepted?

If you filed, it is like dropping it into a mailbox - you cannot get it back.

You'll have wait until your return is either accepted or rejected.

• If rejected, you can make any necessary changes.
• If accepted, you'll need to amend your return. 
• To avoid unnecessary delays, do not amend until your original return has been fully processed.  You will need to print and mail the amendment.  
• Allow 8-12 weeks for processing.

See this TurboTax FAQ for help with amending.

You can check the status of your amended return here, but allow 3 weeks after filing for it to show up.