You may receive a cron notification with the following where IPAddress is your servers public IP and YYYY-MM-DD is the year, month, and day:
The IP IPAddress was already used for a trial license on YYYY-MM-DD
When KernelCare is not licensed and is not eligible for a trial license, you will receive this notification when the following cronjob runs:
# cat /etc/cron.d/kcare-cron
14 */4 * * * root /usr/bin/kcarectl -q --auto-update
Purchase a KernelCare license or uninstall KernelCare.