import bpy
import os

fbxPath = r'Q:\testfbx'

fbxList = os.listdir(fbxPath)
for fbx in fbxList:
    filename = fbx[:-4]
    fbxObj = bpy.ops.import_scene.fbx( filepath = fbxPath+'\\'+fbx )

    objs = bpy.context.selected_objects
    name = ", ".join(o.name for o in objs)
    bpy.data.objects[name].select_set(True)

    bpy.ops.export_scene.gltf( filepath = fbxPath+'\\'+filename+'.glb', export_selected=True)