How to check on the Gadget Usage for Jira DC/Server
Background
How to know which dashboards are using which gadgets and the total count of gadgets.
This information is especially useful for doing impact assessment before migrating to Jira Cloud.
App used
You can use a free Server/DC plugin (App Usage for Jira) which displays the dashboards that contain gadgets
For details, please refer to the Documentation provided by Atlassian.