Rocket.Chat/ee/app/livechat-enterprise/server/hooks/onLoadConfigApi.js

import { callbacks } from '../../../../../app/callbacks';
import { getLivechatQueueInfo, getLivechatCustomFields } from '../lib/Helper';

callbacks.add('livechat.onLoadConfigApi', async (options = {}) => {
	const { room } = options;

	const queueInfo = await getLivechatQueueInfo(room);
	const customFields = getLivechatCustomFields();

	return {
		...queueInfo && { queueInfo },
		...customFields && { customFields },
		...options,
	};
}, callbacks.priority.MEDIUM, 'livechat-on-load-config-api');