index.js

const Realm = require('realm');

//Schemas
const Weapons = {
	name: 'Weapons',
	properties: {
		weaponName: 'string',
		owner: 'string'
	}
};

const Superheroes = {
	name: 'Superheroes',
	properties: {
		name: 'string',
		superPower: 'string',
		weapon: 'string'
	}
};

//setting the credentials
var cred = Realm.Sync.Credentials.usernamePassword("admin", "123");
console.log("credentials set...");

async function main() {
	const currentUser = await Realm.Sync.User.login("https://testinstancerealm.us1.cloud.realm.io", cred)

	console.log("logging user...");
	let config = currentUser.createConfiguration();
	config.schema = [Weapons];
	config.sync.user = currentUser;
	config.sync.url = "realms://testinstancerealm.us1.cloud.realm.io/node-js-test_1";
	config.sync.fullSynchronization = true;
	config.sync.validate_ssl = false;
	console.log("Schema: " + config.schema.name + "\n" +
		"User: " + config.sync.user.name + "\n" +
		"Url: " + config.sync.url + "\n" +
		"FullSync: " + config.sync.fullSynchronization + "\n" +
		"Validate SSL: " + config.sync.validate_ssl + "\n" + "config done...\n");

	const realm = await Realm.open(config);

	console.log("realm opened with configs...")
	let weapons = realm.objects('Weapons');

	realm.write(() => {
		var weapon = realm.create('Weapons',{
			owner: 'Cap',
			weaponName: 'Shield'
		}, true)
	})

	await realm.syncSession.uploadAllLocalChanges();

	console.log("data uploaded")
	process.exit(0);
}

main().catch((err) => {
	console.error(err);
});