Withholding Claim Could Not Be Verified - Kentucky

I filed electronically with TurboTax Home & Business. Seems like Kentucky Department of Revenue didn't receive forms which verify my withholding. What's going on? Text of letter:

 

"Subject:  2020 Individual Income Tax Adjustment

 

Your 2020 Kentucky Individual Income Tax Return was adjusted to $0.00. This adjustment was made for the following reason(s):

 

Withholding claimed could not be verified. Forms W-2, 1099, or PTE-WH or other supporting statements must be submitted to verify withholding claimed.

 

Per KRS 131.110, you have the right to protest an adjustment made by the Department of Revenue. The protest must be in writing, stating reason(s) for the protest, and submitted within sixty (60) days of the original adjustment. Include all documentation necessary to support your protest. "

 

Any help is appreciated. Thanks in advance.