I just tried to run the last line from option 1 "# sudo apt update && sudo apt -y install openvpn-as" and got the following lines...
Reading package lists... Done
Err:1
http://us.archive.ubuntu.com/ubuntu focal InRelease
Temporary failure resolving 'us.archive.ubuntu.com'
Err:2
http://us.archive.ubuntu.com/ubuntu focal-updates InRelease
Temporary failure resolving 'us.archive.ubuntu.com'
Err:3
http://us.archive.ubuntu.com/ubuntu focal-backports InRelease
Temporary failure resolving 'us.archive.ubuntu.com'
Err:4
http://us.archive.ubuntu.com/ubuntu focal-security InRelease
Temporary failure resolving 'us.archive.ubuntu.com'
Reading package lists... Done
Building state information... Done
All packages are up to date.
W: Failed to fetch
http://us.archive.ubuntu.com/ubuntu focal InRelease Temporary failure resolving 'us.archive.ubuntu.com'
W: Failed to fetch
http://us.archive.ubuntu.com/ubuntu focal-updates InRelease Temporary failure resolving 'us.archive.ubuntu.com'
W: Failed to fetch
http://us.archive.ubuntu.com/ubuntu focal-backports InRelease Temporary failure resolving 'us.archive.ubuntu.com'
W: Failed to fetch
http://us.archive.ubuntu.com/ubuntu focal-security InRelease Temporary failure resolving 'us.archive.ubuntu.com'
W: Some index files failed to download. They have been ignored, or old ones used instead.
Reading package lists... Done
Building dependency tree
Reading state information... Done
E: Unable to locate package openvpn-as