LTA claim while filling ITR

I am a salaried individual, and I took a family trip in the last week of March. As a result, I was unable to apply for LTA (Leave Travel Allowance) through my employer(LTA component is present in my salary structure ), as the declaration deadline is in the first week of March. How can I claim this LTA when filing my income tax return online? Do I simply enter the amount under LTA in the ITR without submitting any proof(or where to submit ?) Please let me know.