Issues with hard drive mounting & deluged permissions to write

Check this topic
https://discourse.osmc.tv/t/solved-i-cant-get-tranmission-to-work/1309/10

everything gets automounted in /Media

You want I assume a fixed mount
This explains also how How To Mount A USB Flash Disk On The Raspberry Pi - Raspberry Pi Spy
(it only skips one thing in our OSMC case, you need to unmount it from media first)