How do I turn a employee in for not holding out taxes

Q) How do I turn a employee in for not holding out taxes
A) According to the IRS – Employees who do not have taxes withheld nor remit them personally, are still liable for these taxes and may not qualify for Social Security, Medicare, or unemployment benefits.
Employees who are concerned that their employer is improperly withholding or failing to withhold federal income and employment taxes should report their employer by contacting the IRS at 1-800-829-1040. In cases where the employer withheld employment taxes but failed to deposit them, or failed to issue W-2s, the employee should contact the employer to request the W-2. If the employee is unable to secure a W-2 from the employer, the employee should complete and attach Form 4852, Substitute for W-2, to their tax return using the best information available to calculate the wages and the withholding. This information can often be secured from pay stubs. Source: https://www.irs.gov/compliance/criminal-investigation/employer-and-employee-responsibilities-employment-tax-enforcement