FirebaseFirestore CRUD with bootstrap How

Here is an example of how to perform a CRUD operation using the Firebase PHP library and Bootstrap:

1. First, you will need to install the Firebase PHP library by running the following command 
2. composer require kreait/firebase-php

2. Create a form in Bootstrap to add a new document to a Firestore collection. You can use Bootstrap's form classes to style the form and JavaScript to submit the form data to the PHP script.

<form id="add-form">

  <div class="form-group">

    <label for="name">Name</label>

    <input type="text" class="form-control" id="name" placeholder="Enter name">

  </div>

  <div class="form-group">

    <label for="age">Age</label>

    <input type="number" class="form-control" id="age" placeholder="Enter age">

  </div>

  <button type="submit" class="btn btn-primary">Add</button>

</form>

<script>

  // Add form submit event listener

  document.getElementById("add-form").addEventListener("submit", function(event) {

    event.preventDefault();

    // Get form values

    var name = document.getElementById("name").value;

    var age = document.getElementById("age").value;

    // Send form data to PHP script

    fetch("add.php", {

      method: "POST",

      body: JSON.stringify({ name: name, age: age })

    })

    .then(response => response.json())

    .then(data => {

      // Handle response from PHP script

    });

  });

</script>

3. Create a PHP script (add.php) to handle the form submission and add the data to Firestore:

require __DIR__ . '/vendor/autoload.php';

use Kreait\Firebase\Factory;

use Kreait\Firebase\ServiceAccount;

$serviceAccount = ServiceAccount::fromJsonFile(__DIR__ . '/path/to/service-account.json');

$firebase = (new Factory)

    ->withServiceAccount($serviceAccount)

    ->createFirestore();

$data = json_decode(file_get_contents("php://input"), true);

$docRef = $firebase->collection('users')->newDocument();

$docRef->create([

    'name' => $data['name'],

    'age' => $data['age']

]);

4. Similarly, you can create Bootstrap forms and PHP scripts to handle reading, updating and deleting data from Firestore using the Firebase PHP library.

5. Make sure to include bootstrap CSS and JS in the HTML file where you are trying to render the forms.

Note that the above examples are simplified and may not include error handling or other necessary details for a production application. Also you need to make sure to have the correct credentials and permissions to perform the CRUD operations in your Firestore database