Canned responses are accessible through Issue screens. Look for the Insert template button under the Canned Responses label – clicking it will open a dedicated screen with:
dropdown with search for selecting templates
quick toolbar with your starred templates
text editor with the ability to choose the type of message
Automated actions are not supported in Jira Cloud applications. When using a template that contains an automated action, you’ll be able to use the template as usual, but the automated action won't be executed upon posting the comment.