If you don’t have a vauild Proxmox VE subscription, you will not able to run any APT related command such as apt update, upgrade, install and so on. This blog will show you how to jump over this limit on Proxmox VE.
First, login the Proxmox VE console and go the the shell, then run the follwing command.
Then, add # to comment out the enterprise list, click Ctrl + X and Y to save your change. Then run the following command.
apt update && apt -y full-upgrade
After the first update done, open the source list by using the following command.
Then, add the following code to the end of source list.
deb http://download.proxmox.com/debian buster pve-no-subscription
Finally, run the update command again and reboot your Proxmox VE to enjoy your latest system and have fun with APT.
apt update && apt -y full-upgrade reboot