Get issue security level members

{
  "maxResults": 100,
  "startAt": 0,
  "total": 3,
  "isLast": true,
  "values": [
    {
      "id": 10000,
      "issueSecurityLevelId": 10020,
      "holder": {
        "type": "user",
        "user": {
          "self": "https://your-domain.atlassian.net/rest/api/3/user?accountId=5b10a2844c20165700ede21g",
          "accountId": "5b10a2844c20165700ede21g",
          "emailAddress": "mia@example.com",
          "avatarUrls": {
            "48x48": "https://avatar-management--avatars.server-location.prod.public.atl-paas.net/initials/MK-5.png?size=48&s=48",
            "24x24": "https://avatar-management--avatars.server-location.prod.public.atl-paas.net/initials/MK-5.png?size=24&s=24",
            "16x16": "https://avatar-management--avatars.server-location.prod.public.atl-paas.net/initials/MK-5.png?size=16&s=16",
            "32x32": "https://avatar-management--avatars.server-location.prod.public.atl-paas.net/initials/MK-5.png?size=32&s=32"
          },
          "displayName": "Mia Krystof",
          "active": true,
          "timeZone": "Australia/Sydney"
        },
        "expand": "user"
      }
    },
    {
      "id": 10001,
      "issueSecurityLevelId": 10020,
      "holder": {
        "type": "group",
        "parameter": "jira-core-users",
        "value": "9c559b11-6c5d-4f96-992c-a746cabab28b",
        "expand": "group"
      }
    },
    {
      "id": 10002,
      "issueSecurityLevelId": 10021,
      "holder": {
        "type": "assignee"
      }
    }
  ]
}