LMS connection to NAS Synology

Hi
I installed LMS on a IMac ( Big Sur OS). It’s working fine with my Touch ans 3 Radios.
I stored my high res files on IMac Music folder
So far so good
But I would like to use my NAS Synology to store those files as my IMac drive is almost full
Why I went for LMS on IMac and not Synology? Simply because NAS (DS210+) is too old and addon such Spotty or Tidal are not supported

Issue: I tried to setup a in LMS on IMac with a path to my Synology Music folder but access is nok
Probably something with right access...
I made sure to setup the Music folder in NFS also
Any idea what to do please?
Thanks
Son