State tax filing

I have the same question and confusing.  How can people know whether they have deducted connecticut income tax from federal return?

I live and work in CT. I only have  W2 for the year of 2023. I  take standard deduction.

What exactly should I  be looking for   on my W2? Certain boxes on W2 to indicate this? Or any form I will receive?

 

Thanks