By "employment form" do you mean the W-4 that you give to the employer? Only your employer gets that form. It does not go to the IRS. So your W-4 does not dictate how you have to file your tax return. If you do not have enough withheld from your paycheck to pay tax throughout the year, then you can owe at tax time. If you have enough or more than enough withheld from your paycheck to pay your tax liability then you get a refund at tax time.
https://ttlc.intuit.com/community/tax-topics/help/what-to-know-about-the-new-2020-irs-form-w-4-emplo...
https://www.irs.gov/pub/irs-pdf/fw4.pdf
https://www.irs.gov/individuals/tax-withholding-estimator
**Disclaimer: Every effort has been made to offer the most correct information possible. The poster disclaims any legal responsibility for the accuracy of the information that is contained in this post.**
