There are about two dozen kinds of 1099's. You do not say what kind you are looking for. If you were paid as an independent contractor and the earnings were reported on a 1099Misc, then you need to get a copy from the individual or company that issued the 1099Misc.
Many other 1099's are issued by banks, brokerages, and various types of financial institutions. You could ask for a copy from the entity that issued the 1099, or you may be able to get it online if you have an online account with a password to get it.
I NEED A COPY OF MY W-2 (or 1099)
TurboTax does not have a copy of your W-2—the Wage & Tax Statement—issued to you by your employer, (nor does TurboTax have copies of your 1099’s). You should always save those documents for your own records. You could ask the employer(s) for copies or you can get a copy from Social Security (for a fee of $86).
If you saved a pdf of your completed tax return, the worksheets will show the W-2 information you entered, but not the actual W-2.
To get a copy of a W-2 from Social Security https://faq.ssa.gov/en-us/Topic/article/KA-02501
You can get a wage and income transcript from the IRS: It will not show the actual W-2, 1099’s, etc, but will show the income information the IRS received. It will not, however, show your state information. It will only show the federal information.