Some add-ons are storing JSON formatted data in custom fields. JSON viewer and editor is a more user-friendly tool to display end edit JSON data in custom fields.
If a custom field contains JSON data there will be a little clickable icon. This will be visible in all places where custom fields are used (if it contains JSON data)
Click on the icon to view and edit.
If changes are made validation of the changes must be made. Click the button Validate to validate the changes of the data.
A message will appear if the changes are correct and you can save the changes by clicking on the button Save.
You will receive a message that the changes are saved.