HELP - just bought a 320L and have had this problem from Day 1. Disappointed its not working.
Use the mydlink apps or the mydlink web access - you need to register (free) and link your 320L to the account
That is the easiest way - allowing others access is a bit more problematic
If just access to your files - the easiest option is to give them the account details (email/password) but that could in turn cause security issues - you could set user account (with folder restrictions) on the web gui but I don't think it's easy to access.
What I have tested so far that works is install QuiXplorer addon then on the other PC/laptop - sign into mydlink web access and click "My Files" - if I remember correctly it should give a web IP address then/web/******* change the web address to (
hopefully) "ip address/QuiXplorer/index2.php?action=login&order=name&srt=yes" and it should automatically go to login page of QuiXplorer
If it's just media files you want to share, I've seen it working but I have not been able to get it working myself Kodi and Emby. Emby allows sharing online of media database/files
HTH
If I haven't completely answered your question or you need further advice - don't be afraid to ask.