That is a scam phone call. Do not respond. You will never receive a call from the IRS.
https://www.irs.gov/uac/IRS-Urges-Public-to-Stay-Alert-for-Scam-Phone-Calls
Disclaimer: Not a tax professional. Information gathered from internet links. Anything dated in June 2019 was posted in prior years and is before the 2019 limits and changes.
