First, enable enable the Insight custom field feature, you can complete the following steps:
Navigate to the Custom Charts - Settings page, and open the Data sources tab
From the top navigation bar in Jira, choose Apps > Manage your apps
Choose Custom Charts - Settings in the Custom Charts section of the Apps page
From the Custom Charts - Settings page, choose Data sources
Find the Insight custom fields panel and click the grey down arrow to expand it
On the right side of the section, click the grey toggle to enable the feature (it’s enabled once the toggle turns green)
In the Email box, enter the email address of the user whose permissions will be used to load the Insight custom fields
Reminder: This user must have a valid Jira Service Management license. They do not require any additional Insight-specific permissions.
In the API token box, enter the API token for this user
Atlassian documentation on creating an API token: https://support.atlassian.com/atlassian-account/docs/manage-api-tokens-for-your-atlassian-account/
Click Test connection then Save once you’ve connection is confirmed
Select the Jira Groups with users who should be able to view Insight custom field data in Custom Charts
Users who are not in these groups will simply see the Insight object ID instead of the object name while viewing charts