Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal/InRelease Temporary failure resolving 'archive.ubuntu.com' code example

Example 1: Failed to fetch http://archive.ubuntu.com/ubuntu/dists/focal/InRelease

Check your internet connection, your VPN or any antivirus which could be
creating the conflict ;)

Example 2: emporary failure resolving

echo "nameserver 8.8.8.8" | sudo tee /etc/resolv.conf > /dev/null
#this is temporary solution