This just means that the IRS is currently processing your return. Most refunds will issued within 21 days or less. However, some returns may take more time for the IRS to review. There's no way of knowing exactly when the IRS will update. Some returns may take more time for the IRS to review. You will need to keep checking the Where’s My Federal Refund? tool for updates. Updates are made daily, usually overnight.
https://ttlc.intuit.com/replies/3332479
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/replies/3302084