Load multiple GPX files to Leaflet map

Considering I have a folder that contains multiple .gpx tracks, my objective is to show each of them in a single leaflet map. Then I would personalize thing like tooltips of each track, the color for each track, etc.

I already searched and found these libraries:

https://github.com/mapbox/leaflet-omnivore

https://github.com/mpetazzoni/leaflet-gpx

But they only let me load one track. Is there a way to load an entire folder?

If leaflet does not allow it, is there another option?

EDIT:

So I have the tracks folder on my backend/server side, so to read them at the frontend I need some way to get the data.

My backend runs using Flask, and I got an endpoint to list all the files:

class GPS_Tracks(Resource):
  def get(self):
      files =[]
      for f in os.listdir(files_directory):
        if f.endswith(".gpx"):
          files.append(f)
      files.sort()
      return files

It returns something like this:

[
    "2016-01-15 17-43-20.gpx", 
    "2016-01-15 18-34-15.gpx", 
    "2016-01-16 21-36-19.gpx", 
    "2016-01-16 21-48-17.gpx", 
    "2016-01-16 22-58-56.gpx",
...]

So my frontend does a request to that endpoint and gets the names of the files. But I need to still access the files.