Reg advance tax payment

A former central government employee who retired in June 2019 is seeking clarification on paying income tax after their office did not deduct it. They owe Rs 80,000 and want to know if they can pay this before filing their ITR 1 form, having not paid any advance tax. The response indicates that interest under sections 234B and 234C will apply, and the tax along with interest must be paid before filing the return, with payment details noted in the ITR.