following the instructions on the official vpn page (instructions install openvpn client) in the second step:
# curl -fsSL https://swupdate.openvpn.net/repos/openvpn-repo-pkg-key.pub | gpg --dearmor > /etc/apt/trusted.gpg.d/openvpn-repo-pkg-keyring.gpg
I get the following error message:
sudo curl -fsSL https://swupdate.openvpn.net/repos/openvpn-repo-pkg-key.pub | gpg --dearmor > /etc/apt/trusted.gpg.d/openvpn-repo-pkg-keyring.gpg
-bash: /etc/apt/trusted.gpg.d/openvpn-repo-pkg-keyring.gpg: Permission denied
(23) Failed writing body
I had a similar issue recently. Use
sudo wget https://swupdate.openvpn.net/repos/openvpn-repo-pkg-key.pub
and
sudo apt-key add openvpn-repo-pkg-key.pub
Reference - https://openvpn.net/cloud-docs/openvpn-3-client-for-linux/