`salt`: Initializing an `aur.chaos.cx`-using Archlinux (offline) template - Using the update proxy for `gpg` keys et al

[apparatus]

@balin1

I also fail to do so, BTW, from within the template using curl or wget as e.g. advised here.

Did you try to curl/wget some other sites for a test?
Check if tinyproxy is running in sys-whonix and check if qubes-updates-proxy service is enabled for sys-whonix:

Update templateVM through vpn-proxy

This suggests you haven’t enabled the proxy in the vpn qube - the service is tinyproxy Depending on how you set up the proxy, it’s also possible that your firewall configuration on the vpn-proxy is blocking traffic to/from tinyproxy. Try enabling the service with qvm-service and see if that works - if not, you’ll need to provide more information.