When I only used my smartphone, I couldn't get it to work either. I took a PC and did the following:
1. Go to Strava.com and log in
2. Go to https://nomi.cz/strava/ and click the kml link
3. Authorize Strava the needed permission
4. Download the kml file
5. Copy it on the Smartphone (USB, E-Mail, Dropbox etc.)
6. Using a file explorer on android move the kml file to .../Locus/mapItems/ (My path was for example /extSD/Android/data/menion.android.locus.pro/files/Locus/mapItems/
7. In Locus go to the menu where you can see you points and tracks, there is a third tab, there you can select you kml file, if its not showing restart Locus or find the correct Locus folder
8. Move the map a bit to trigger the download
Thank you! But that's the thing, when I go into nomi.cz/strava and press the link to the KML I either get to the strava logon page (if I'm not logged into strava) and if I'm logged in/log in with my information I get an error 400 in internet explorer and the text "when expecting a Text, encountered Null instead" in Chrome. And by kml file, do you mean only that file or all of the files associated to it?
If anyone could upload the kml file again I'd very much appreciate it, because I think that I gave the app permission to use my strava last time. I didn't get the KML that time though.
Many thanks in advance!