To install the app you will need to be an administrator of your Jira instance.
Visit the marketplace listing - https://marketplace.atlassian.com/apps/1230997 and click the “Get it now“ button
Wait for the installation to finish.
This adds the app to your Jira instance and you are ready to use it. Next, read Finding Time in Status Report Dashboard Gadget on where to find the app in Jira.