ubuntu snap permission problem

[Kevin Lynch]

I use an oracle virtualbox CLI, I've upgraded it to focal fossa,
consequently I'm installing via snap.

If I set the default directory to save file as unix my home directory
all works well. However when I specify to write my media to a folder
that is a shared folder from windows.
kevin at focalfossa:/media/sf_iPlayer_Recordings$ mount | grep -i iplayer
/var/lib/snapd/snaps/get-iplayer_250.snap on /snap/get-iplayer/250
type squashfs (ro,nodev,relatime,x-gdu.hide)
iPlayer_Recordings on /media/sf_iPlayer_Recordings type vboxsf
(rw,nodev,relatime,iocharset=utf8,uid=0,gid=998,dmode=0770,fmode=0770,tag=VBoxAutomounter)
nsfs on /run/snapd/ns/get-iplayer.mnt type nsfs (rw)
kevin at focalfossa:/media/sf_iPlayer_Recordings$ get_iplayer --pid m000lhwf -o .
get_iplayer v3.26, Copyright (C) 2008-2010 Phil Lewis
  This program comes with ABSOLUTELY NO WARRANTY; for details use --warranty.
  This is free software, and you are welcome to redistribute it under certain
  conditions; use --conditions for details.


Episodes:
Newsnight - 03/08/2020, BBC Two, m000lhwf
INFO: 1 total programmes

WARNING: A UK TV licence is required to access BBC iPlayer TV content legally
INFO: Downloading tv: 'Newsnight - 87. 03/08/2020 (m000lhwf) [original]'
ERROR: Cannot open (write):
/media/sf_iPlayer_Recordings/Newsnight_-_87._2020-08-03_m000lhwf_original.video.ts
kevin at focalfossa:/media/sf_iPlayer_Recordings$


What is the best method to grant my get_iplayer access to the external
filesystem?

TIA

Kevin