You can use your backups on ePsxe using the following method:
- Retrieve your backup file from ePSXe (Epsxe/memcards/Your_Backup.mcr).
- Identify the exact name of your rom.
- Rename the file
Your_Backup.mcr to YourRomName.srm.
- Move your freshly renamed file to the
/recalbox/share/saves/psx folder in your Recalbox.