Your 2019 return you filed last year or your 2020 return?
Did you go all the way through the File tab, through the 3 steps and hit the big orange Transmit Returns Now button?
If you used the Online version you can check your 2020 efile status here
When you efile you get back 2 emails. The first email only confirms the transmission. The second email says if the IRS (or state) Accepted or Rejected your efile.
When you log into your account you should also see the status and if it was Accepted or Rejected, Started, Printed, Ready to Mail, etc. What does it say?
Check Where's My Refund to see if your return has been processed. Sometimes taxpayers are expecting a refund, but the money gets offset by past due child support or other debts. If a check was sent and not received, then the IRS can put a trace on it.
Only the IRS can tell you what is going on with your refund.
How to contact the IRS