Can LTC cash voucher scheme claims be made directly in ITR?

My employer takes the tax savings proofs for a financial year by January 15th.

Since LTC cash voucher scheme accepts the tax proofs till March 31st , how can i claim the benefits for the bills generated between January 15 to March 31? Can these be claimed in ITR directly?

I have read on various platform that the LTA/LTC claims can only be claimed via employer.

Please help