supply to sez without payment of tax

Can apply for LUT now for the exports already made..

Benefit cannot be taken away for the procedural lapse/delay..

refer Circular No. 37/11/2018-GST

https://www.eepcindia.org/download/180316102131.pdf

4.1. In this regard, it is emphasised that the substantive benefits of zero rating may not be denied where it has been established that exports in terms of the relevant provisions have been made. The delay in furnishing of LUT in such cases may be condoned and the facility for export under LUT may be allowed on ex post facto basis taking into account the facts and circumstances of each case.