Are you an employer or an employee? The employer is responsible for sending out the correct W-2 form, but W-2s for 2019 won't be sent to employees until next January. Or do you mean W-4? If you are an employee Form W-4 is the form that you give your employer to determine how much tax will be withheld from your pay. You can download Form W-4 for 2019 from the following link.
https://www.irs.gov/pub/irs-pdf/fw4.pdf