Go to Admin--> Canned Response--> Go into the Canned Response--> Scroll down to the bottom of the page--> Choose 'All Agents'--> Save the changes. You can also display it to agents in specific groups as well.


Please note that, only the admin of the helpdesk will be able to share the canned responses with the all the agents. If you are an non-admin agent who is looking to share canned response with your co-worker, you can request the admin to create canned responses for the helpdesk and ask them to share it with All agents.