You can import gpx files into Google maps but need to do it on a computer, don't think that functionality is available on phones.
Edit: just tried, and you can do it by going to maps in the browser and forcing it to open the desktop site, then going to 'your places' in the menu, 'see all maps', then add new map and upload a gpx file from in there and save. Can then copy and share the link. But it's clunky, may be easier to use
this app
Or you can just share a gpx file - and people can use an app like
GPX Viewer on their phones to view