Jira uses the "Flagged" field and it can be applied to any issue type like Story or Epic.
In Kendis you can enable that field
Go to "Board Settings --> Edit Board Settings --> Additional Fields"
Click on the checkbox "Enable Jira Flagged/Blocked Field"
You can enable this field for both Kendis only cards and Jira cards
Select the field name from Jira
Note: Default Jira field is "Flagged", select this field unless you have customized that in Jira and using a different field.
How to View Flag Icon
When a feature (Epic) is flagged, a small red flag will be visible on the card
If a story under a feature is flagged, there is an orange flag visible
It is possible to filter the stories or features (Epics) that are flagged on your board.
Click on the More Filters
Select the "Flagged" option.
After enabling this field when I open for edit I don't see the "Impediment" checkbox.
Answer: If the "Flagged" field is not enabled in Jira for your issue type and project, Kendis will not show this option. You must go to Jira and make sure the "Flagged" field is enabled for your issue type and project.
After enabling the Flagged field in Jira, it still doesn't show up at Kendis?
Make sure you have updated "Project Meta" by going to "Board Settings --> Edit Board Settings --> Jira Meta"