Newbie needs help installing WebDav and BorgBackup

Hello,

I am a newbie in OMV. I have installed OMV 5.0.5 and currently running omv 5.0.14-1 and activated omvextras. I have updated package, omv and omvextra through web interface. I do not see any errors. Only arrakis-testing repository reports no release file.

I am running 4.19.0-6 kernel. Kernel is not being hold.

However under plugin section I can not see webdav, borgbackup and duplicati even though it is reported on http://www.omv-extra.org web site. /etc/apt/sources.list.d/omvextras.list file is follows.

deb https://dl.bintray.com/openmediavault-plugin-developers/usul buster main
deb https://dl.bintray.com/openmediavault-plugin-developers/usul-testing buster main
deb https://dl.bintray.com/openmediavault-plugin-developers/usul-extras buster main
deb https://dl.bintray.com/openmediavault-plugin-developers/arrakis buster main
deb https://dl.bintray.com/openmediavault-plugin-developers/arrakis-testing buster main
deb https://download.docker.com/linux/debian buster stable
deb http://linux.teamviewer.com/deb stable main

I appreciate any help.

Thank you for the response.... Maybe this should be a new thread but I am just trying to build a new machine with OMV. Do you advise to install OMV 5 or OMV 4...