Why is my refund not found?

I presume are asking about a Federal refund and using the IRS "Where's My Refund" tool.

How did you file--did you efile, or did you choose to print and mail your return?   If you printed and mailed the return, it takes 4 weeks to show up in that WMR tool.

If you efiled, first be sure you successfully filed.   Log in to your Online TurboTax account and confirm at the Tax Home that your efiled return was accepted.

NOTE:  If you only recently efiled, you have to wait at least 24 hours after being accepted before using the IRS tool.

When using the IRS WMR tool, be sure SSN and filing status are entered correctly.
https://www.irs.gov/Refunds

Use only the Federal refund amount.  Do not use any combined total refund figure that includes the state refund.

Look at your actual 2019 return to get the Federal refund amount.  Be sure you are using what is displayed on your Federal Form 1040, Line 21a for the Federal refund amount.

And if you are paying your fees out of the Federal refund, use the Federal amount without regard to the fee subtraction; i.e., the amount before any fees are subtracted.