What do you mean?
Cheap way would be to jump the high beam signal to the low beam and see if it lights up then you will know if it’s the switch or the bulb.
Depending on the style of the bulb it could have 3 prongs which would make it easy. H7’s are that way IIRC.
Otherwise just buy a $11 bulb at nearest parts store. If it doesn’t work try to return it.