A simple way to test this would be:
HTTPS_PROXY=http://192.168.x.x curl -m10 -i https://ifconfig.me
If that works, it should work for Certbot as well.
If it doesn't, then you need to correct the proxy URL.
A simple way to test this would be:
HTTPS_PROXY=http://192.168.x.x curl -m10 -i https://ifconfig.me
If that works, it should work for Certbot as well.
If it doesn't, then you need to correct the proxy URL.