This means that your tax return is still being processed. With the new tax laws and updates, the IRS is taking every precaution to ensure each tax return is process correctly and fully. There's no way to know when the IRS will update to refund approved. Until the IRS starts processing your tax return on their own, you may not find record of it or the website may say that you have put in incorrect information when tracking your federal refund. As your return moves through the system, the status of it will be updated accordingly. Continue checking the Where’s My Federal Refund? tool for updates. Updates are made daily, usually overnight. You may also download the IRS2Go app to check your Federal refund status
If your return was accepted 21 days ago or more and you have not received an update via the Where's My Refund tool, you can follow the instructions in the following FAQ to contact the IRS for further assistance.
https://ttlc.intuit.com/community/refund-status/help/what-if-my-irs-refund-is-taking-longer-than-21-days/00/26080