Js Snclient

const response = await repository.security.getRelatedIdentities({
  contentIdOrPath: '/Root/Content/IT',
  level: 'AllowedOrDenied', // or PermissionLevel.AllowedOrDenied from @sensenet/default-content-types package
  kind: 'Groups' // or IdentityKind.Groups from @sensenet/default-content-types package
})