How to remove subscription alert from Proxmox 6

Remove paid repository:
rm /etc/apt/sources.list.d/pve-enterprise.list

Add non-subsriber repo:
echo "deb http://download.proxmox.com/debian/pve buster pve-no-subscription" > /etc/apt/sources.list.d/pve-install-repo.list

Update system and reboot:
apt update && apt full-upgrade
reboot

Remove "You do not have a valid subscription for this server. Please visit www.proxmox.com to get a list of available options." message:
sed -i.bak "s/data.status !== 'Active'/false/g" /usr/share/javascript/proxmox-widget-toolkit/proxmoxlib.js && systemctl restart pveproxy.service