Please help need to show count of unique value instead of count only

Hi I want to show count of unique value instead of count only.

=COUNTIFS(Data!$A:$A,CONCATENATE(A8,B8),Data!$T:$T,"<>No Confirmation Date",Data!$T:$T,"<>")

Please help me in modifications in this formulae.

Attach a sample workbook (not a picture or pasted copy). Make sure there is just enough data to demonstrate your need. Include a BEFORE sheet and an AFTER sheet in the workbook if needed to show the process you're trying to complete or automate. Make sure your desired results are shown, mock them up manually if necessary.

Remember to desensitize the data.

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