Litek :)

modulesis an array containing objects (if that does not ring a bell you should consider going a bit into javascript before moving much further).

The structure of this array is like this:

modules: [
  {
    module: '',
    position: '...',
    config: {
     ...
    },
  },
  {
    module: '',
    position: '...',
    config: {
     ...
    },
  },
  {
    module: '',
    position: '...',
    config: {
     ...
    },
  }
]

You need to take care to use commas as seperators, IN an array or an object, semicolons are always misplaced.
Hope that helps.

Please

/* Magic Mirror Config Sample
 *
 * By Michael Teeuw https://michaelteeuw.nl
 * MIT Licensed.
 *
 * For more information on how you can configure this file
 * See https://github.com/MichMich/MagicMirror#configuration
 *
 */

var config = {
	address: "localhost", 	// Address to listen on, can be:
							// - "localhost", "127.0.0.1", "::1" to listen on loopback interface
							// - another specific IPv4/6 to listen on a specific interface
							// - "0.0.0.0", "::" to listen on any interface
							// Default, when address config is left out or empty, is "localhost"
	port: 8080,
	basePath: "/", 	// The URL path where MagicMirror is hosted. If you are using a Reverse proxy
					// you must set the sub path here. basePath must end with a /
	ipWhitelist: ["127.0.0.1", "::ffff:127.0.0.1", "::1"], 	// Set [] to allow all IP addresses
															// or add a specific IPv4 of 192.168.1.5 :
															// ["127.0.0.1", "::ffff:127.0.0.1", "::1", "::ffff:192.168.1.5"],
															// or IPv4 range of 192.168.3.0 --> 192.168.3.15 use CIDR format :
															// ["127.0.0.1", "::ffff:127.0.0.1", "::1", "::ffff:192.168.3.0/28"],

	useHttps: false, 		// Support HTTPS or not, default "false" will use HTTP
	httpsPrivateKey: "", 	// HTTPS private key path, only require when useHttps is true
	httpsCertificate: "", 	// HTTPS Certificate path, only require when useHttps is true

	language: "en",
	logLevel: ["INFO", "LOG", "WARN", "ERROR"], // Add "DEBUG" for even more logging
	timeFormat: 24,
	units: "metric",
	// serverOnly:  true/false/"local" ,
	// local for armv6l processors, default
	//   starts serveronly and then starts chrome browser
	// false, default for all NON-armv6l devices
	// true, force serveronly mode, because you want to.. no UI on this device

	modules: [
		{
			module: "alert",
		},
		{
			module: "updatenotification",
			position: "top_bar"
		},
		{
			module: "clock",
			position: "top_left"
		},
		{
			module: "calendar",
			header: "US Holidays",
			position: "top_left",
			config: {
				calendars: [
					{
						symbol: "calendar-check",
						url: "webcal://www.calendarlabs.com/ical-calendar/ics/76/US_Holidays.ics"					}
				]
			}
		},
		{
			module: "compliments",
			position: "lower_third"
		},
		{
			module: "currentweather",
			position: "top_right",
			config: {
				location: "New York",
				locationID: "5128581", //ID from http://bulk.openweathermap.org/sample/city.list.json.gz; unzip the gz file and find your city
				appid: "YOUR_OPENWEATHER_API_KEY"
			}
		},
		{
			module: "weatherforecast",
			position: "top_right",
			header: "Weather Forecast",
			config: {
				location: "New York",
				locationID: "5128581", //ID from http://bulk.openweathermap.org/sample/city.list.json.gz; unzip the gz file and find your city
				appid: "YOUR_OPENWEATHER_API_KEY"
			}
		},
		{
			module: "newsfeed",
			position: "bottom_bar",
			config: {
				feeds: [
					{
						title: "New York Times",
						url: "https://rss.nytimes.com/services/xml/rss/nyt/HomePage.xml"
					}
				],
				showSourceTitle: true,
				showPublishDate: true,
				broadcastNewsFeeds: true,
				broadcastNewsUpdates: true
			}
		},
	]
};

	module: "MMM-ImagesPhotos",
	position: "middle_center",
	config: {
		opacity: 0.9,
		animationSpeed: 500,
		updateInterval: 5000,
	}
/*************** DO NOT EDIT THE LINE BELOW ***************/
if (typeof module !== "undefined") {module.exports = config;}

[29.03.2021 18:15.24.533] [ERROR] WARNING! Could not validate config file. Starting with default configuration. Please correct syntax errors at or above this line: /home/pi/MagicMirror/config/config.js:107
	position: "middle_center",
	        ^

SyntaxError: Unexpected token ':'
    at Module._compile (internal/modules/cjs/loader.js:896:18)
    at Object.Module._extensions..js (internal/modules/cjs/loader.js:986:10)
    at Module.load (internal/modules/cjs/loader.js:816:32)
    at Module._load (internal/modules/cjs/loader.js:728:14)
    at Function.Module._load (electron/js2c/asar.js:748:26)
    at Module.require (internal/modules/cjs/loader.js:853:19)
    at require (internal/modules/cjs/helpers.js:74:18)
    at loadConfig (/home/pi/MagicMirror/js/app.js:70:12)
    at App.start (/home/pi/MagicMirror/js/app.js:217:3)
    at Object.<anonymous> (/home/pi/MagicMirror/js/electron.js:129:7)

Need some help

this is the end of the config.js file

		{
			module: "newsfeed",
			position: "bottom_bar",
			config: {
				feeds: [
					{
						title: "New York Times",
						url: "https://rss.nytimes.com/services/xml/rss/nyt/HomePage.xml"
					}
				],
				showSourceTitle: true,
				showPublishDate: true,
				broadcastNewsFeeds: true,
				broadcastNewsUpdates: true
			}
		},
	]      // < ------- this is the end of the module list (the start is [ above
};

so, you place your new module BEFORE the end of the list and AFTER the } of the prior module

		{
			module: "newsfeed",
			position: "bottom_bar",
			config: {
				feeds: [
					{
						title: "New York Times",
						url: "https://rss.nytimes.com/services/xml/rss/nyt/HomePage.xml"
					}
				],
				showSourceTitle: true,
				showPublishDate: true,
				broadcastNewsFeeds: true,
				broadcastNewsUpdates: true
			}
		},  // < --- end of prior module 
// new module goes here 
{
	module: "MMM-ImagesPhotos",
	position: "middle_center",
	config: {
		opacity: 0.9,
		animationSpeed: 500,
		updateInterval: 5000,
	}
},
	]   // < --- end of module list 
};

ALWAYS check to make sure end of prior module entry } ends with a comma (means more to follow)

Here is an example of an entry in config.js

{
	module: "MMM-ImagesPhotos",
	position: "middle_center",
	config: {
		opacity: 0.9,
		animationSpeed: 500,
		updateInterval: 5000,
	}
},

just a little section

{
   module: "?????",
   position:"??!!!??",
   config :{
     .
     .
   }
}

see the topics on my signature below