WA-api/api/message/services/message.js

'use strict';

/**
 * Read the documentation (https://strapi.io/documentation/developer-docs/latest/concepts/services.html#core-services)
 * to customize this service
 */

module.exports = {
	distinctbyKey: async (params) =>{
		const results = await strapi.query('message').find(params);
		let arrKeys = [];
		results.forEach((i)=>{
			if(!arrKeys.includes(i["session_datum_key"])) arrKeys.push(i["session_datum_key"]);
		});
		return arrKeys
	}
};