How can I check if I entered Form 1098-T in my 2023 tax return?

There is no requirement to enter the 1098-T, just because you got one. The 1098-T is only an informational document. The numbers on it are not required to be entered onto your tax return. However receipt of a 1098-T frequently means you are either eligible for a tuition credit or possibly the student has taxable scholarship income. 

If you claimed a credit there will be an entry on line 29 and/or line 20 of your form 1040.  If you reported taxable scholarship, it will be on line 8r of Schedule 1(on the student's return).

Details on the tuition credit show on form 8863.  If you entered the 1098-T and TurboTax didn't claim anything, the 1098-T will be on your forms list.