Distribution on Mac

Hi! We launched a game called “The Lost War” on Windows, Linux and Mac. We built it using Unity and exported it to all operating systems. We just got approved for Epic Games Store publication as well. The app downloads and runs smoothly on Windows but fails on Mac. Users get an “LS-0013” error message and cannot open the application. Is this a code signage problem or one that I can solve on Epic Games Store itself? Looking for any help, thank you!