How to install VST plugins to Flatpak Audacity?

I want to install the GVST plugin pack so that Audacity (from Flatpak) can see it. I am using KDE Neon (fairly new, I'm not sure how to find the version number). I've tried various directories to copy the .so plugins to, but so far no success. I have restarted Audacity each try to make sure it refreshed everything. If possible, I'd like other VST supporting Flatpak apps to see the plugins also.