Messenger needs to be enabled and users must also be given permission to access it.
To enable Messenger, go to Actions > Configure > Site Settings > Applications and turn on Messenger.
Then, from the main company homepage, open the page options in the top-right corner and select Manage Security or Manage Permissions. Use Advanced Permissions and open the Messenger tab to assign access to the required users. To give access to everyone, you can use the Active Intranet Users system group.
Once access has been granted, users will see the chat icon in the top-right corner of Oak and on the mobile app.