Ok a 5.1 jar is out, you can either download this and stick it in your addons folder AFTER removing the old version first
Or you can update the version in place directly from my repo using the openHAB cli like
update org.openhab.binding.amazonechocontrol https://github.com/digitaldan/openhab-addons/releases/download/amazonechocontrol-auth/org.openhab.binding.amazonechocontrol-5.1.0-SNAPSHOT.jar
Note that if you upgrade your system, it will overwrite installing from the CLI just FYI (so its not as permanent as adding to addons)