For the Jira admins

  1. Install the Calendar Heatmap Gadget app

You may want to check out /wiki/spaces/SUPPORT/pages/7253688322 too (blue star)

For the Jira users

  1. Add a Calendar Heatmap Gadget to the dashboard

  2. Perform 1-time approval for the app to access data on behalf of the user

This is required for all apps built with Atlassian Forge