Commercial software
Consult HyperSync manual for achieving synchronisation between Explore amplifier and LSL.
Then follow the E-Prime® guidelines on sending markers via LSL.
https://support.pstnet.com/hc/en-us/articles/4411440563479-INFO-Lab-Streaming-Layer-LSL-38955
https://github.com/PsychologySoftwareTools/eprime3-lsl-package-file