I have configured alerts for vessel and ports to appear on Messenger but unable to view them in Messenger specifically. I do see them as alerts in Eikon but not in Messenger.
@Vini When you set an alert you should have a number of options to specify how you wish to be alerted. In those you can specify Messenger as well as email etc - sorry the screenshot below is from Workspace but it will be similar in Eikon:
I hope this can help.