My federal tax return status is set to being reviewed to protect against "Identity theft" when checking the IRS tax tracker. They are asking for verificationbutdontsayhow

My refund status is "To protect you from identity theft, your tax return is currently being reviewed. To help us process your return more quickly, please verify your identity and tax return information. blahblahblah" it never said that to me before? Is it being delayed? It doesn't say how to verify. Does anybody have an idea?