Study this page from IRS. I'm in the same situation as your but for Tax year 2020. Sounds like you need to refile because it's for year 2019.
https://www.irs.gov/individuals/understanding-your-cp80-notice
Due to processing delays for 2019 and 2020 tax returns, the issuance of CP80 and CP080 (Unfiled Tax Return – Credit on Account) notices has been suspended. If you receive a notice for your 2019 return and you filed more than six months ago, please refile the return. If you receive a notice for your 2020 return DO NOT refile.
