I did extend my program MakeMap (see also this thread with the possibility to use an OpenStreetMap for the display of photo locations and a route recorded in a gpx-file. No API-key is required for this display method.
If you like to display a gpx-file, you should convert it to a track.js file with my program ConvertTrack.
Program MakeMap can be used with the Turtle and Tiger skin and with my skins: Slide Show 4 skin, FancyBox skin, PhotoSwipe skin and LightGallery skin (more skins can be added on request).
With the last 3 skins you can also show the location in OpenStreetMap via a location button in the slide page, see this example album.