How to use Livewire component inside of javascript?

Looking at docs https://laravel-livewire.com/docs/2.x/events#from-js working with Livewire component inside of javascript

<script>
    Livewire.emit('postAdded')
</script>

I do not see what Livewire is ? Declared var ? How can I get it. I need from JS code get value of some var and run component method. How can I do it?

Modified Block # 2:

Defining in template of my component :

<div class="admin_page_container" id="facilities_admin_page_container">
   ...

In method of my alpinejs component I do

function adminFacilitiesComponent() {
    return {
        getSubmitLabel: function (component) {
            const doc = document.getElementById("facilities_admin_page_container");
            console.log('doc::')
            console.log(doc)

            var updateMode = window.livewire.find(doc.getAttribute("wire:updateMode"))
            // But I got error : index.js:31 Uncaught (in promise) TypeError: Cannot read property '$wire' of undefined
            // I see content of doc in browser's console : https://prnt.sc/1sdu4f1
            console.log('updateMode::')
            console.log(updateMode)

In my component I have defined :

namespace App\Http\Livewire\Admin;

...
class Facilities extends Component
{
    ...
    public $updateMode = 'browse';

I just try to get value of $updateMode in JS getSubmitLabel function...

Thanks!

Solution

To answer your question where the livewire global object is comming from: you injected livewire scripts in the body of your layout:

<html>
<head>
    ...
    @livewireStyles
</head>
<body>
    ...
    @livewireScripts
</body>
</html>

https://laravel-livewire.com/docs/2.x/installation

The livewire global object is available via window.Livewire. The method you are looking for is probably

 Livewire.emitTo(componentName, eventName, ...params)

Make sure that the livewire object is actually available when you are calling this method.

For all available methods see https://laravel-livewire.com/docs/2.x/reference

To get a component in javascript try:

const doc = document.getElementById("myComponent");
window.livewire.find(doc.getAttribute("wire:id"))