For tax year 2023?
Did you enter the amount paid to you by the employer on the 2023 tax return and file the 2023 tax return?
If you did not report the the income on the 2023 tax return that was filed you will need to amend the 2023 tax return.
See this TurboTax support FAQ for amending a prior year tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-already-filed/L4VjJ9BA2_US_en_US?uid=ld1n99kr
If you have not filed the 2023 tax return -
To complete and file a 2023 tax return using TurboTax you would need to purchase, download and install on a personal computer one of the 2023 desktop editions from this website - https://turbotax.intuit.com/personal-taxes/past-years-products/
A 2023 tax return can only be printed and mailed, it cannot be e-filed using TurboTax.
If you received income in 2023 that was not included on your tax return, you will need to amend that return to include the 1099 (is it a 1099NEC?) that you will be picking up. You do NOT put 2023 income on a 2024 tax return. And...if you are receiving a 1099, you did not have an employer---you had a client and are receiving self-employment income from that work. You will pay self-employment tax for Social Security and Medicare.
Wait until your original return has been fully processed before you amend, and make sure you have saved a pdf of the original return before you amend.
See this TurboTax support FAQ for amending a tax return - https://ttlc.intuit.com/turbotax-support/en-us/help-article/tax-return/amend-change-correct-return-a...
Do not expect quick results from amending. It can take four months or more for the IRS to process an amended return.
You can watch for information here:
https://www.irs.gov/Filing/Individuals/Amended-Returns-(Form-1040-X)/Wheres-My-Amended-Return-1