Singular:
There is an update available for %1$s but your license has expired. %2$sVisit the Events Calendar website to renew your license.%3$s There is an update available for %1$s but your license has expired. %2$sVisit the Events Calendar website to renew your license.%3$s

Plural:
Updates are available for %1$s but your license keys have expired. %2$sVisit the Events Calendar website to renew your licenses.%3$s Updates are available for %1$s but your license keys have expired. %2$sVisit the Events Calendar website to renew your licenses.%3$s

This plural form is used for numbers like: 1, 21, 31

This plural form is used for numbers like: 2, 3, 4

This plural form is used for numbers like: 0, 5, 6