Form 1099-NEC would typically be mailed by the payer (who, by the way, wouldn't be considered your employer), generally by the end of January.
Contact the payer to try and get the document. If you have no luck with that, you can contact the IRS for help. See Let Us Help You for contact information.
That said, receiving the 1099-NEC isn't necessarily critical to filing your return, if you know the amount of income you received. If the income is considered self-employment -- that is, you were a contractor for this person -- you'd simply enter it as self-employment income.
To enter your self-employment income and expenses in TurboTax Online: