A W-4 is the form you filled out for your employer to tell them how much to withhold from your paycheck. Only the employer has that.
Are you asking for your W-2?
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.
https://www.irs.gov/individuals/get-transcript
https://ttlc.intuit.com/questions/2561916-how-can-i-get-a-copy-of-my-w-2
I assume you are asking about a 2018 W-2 rather than a W-4. TurboTax does not have W-2s, but you can open your 2018 tax form and look at the information you entered from you W-2 when you filed it. Here is how to access prior year returns filed using the online product: https://ttlc.intuit.com/community/prior-year-return/help/how-do-i-access-my-prior-year-return/00/27010
If you filed using the CD/download product, the only copy of your tax return is on your computer. If you saved a copy of your tax return with all the documents, you should be able to find the pdf of the return on your computer.
You can get a W-2 transcript from the IRS using this link: https://www.irs.gov/taxtopics/tc159