How to create your first operation

Go to the Jira administration and click on Marketplace apps. Select Manage Operations in the sidebar on the left.

Add Operation

On the "Manage Operations" page, click Add Operation.

Enter a name for your first operation, e.g. Create test comment
Optionally enter a description
In the triggers input select Manual
Click Save

Add Step

To add a step to an newly created operation, click Add Step next to the new operation in the Steps column on the "Manage Operations" page.

You can leave the name empty.
In the action input select Create a comment
In the template input enter:
This is a test comment on ${issue.key}.
Click Save

Use your first operation

Navigate to any work item or create a new one.
Click on the action menu (...) at the top right.
Select Publish issue
Select your new operation, e.g. Create test comment, and click next
Click confirm to start your operation
Click close. The page will be reloaded automatically and you should see the new test comment.