Woocommerce checkout fetch update checkout

<script>
			window.addEventListener('load', function () {
	
				document.getElementById("amount_number").addEventListener("blur", function() {
					let inputValue = this.value ;
					console.log(inputValue);

					const dataluq = new FormData();
					dataluq.append( 'action', 'woochargesiusersetamount' );
					dataluq.append( 'amount_number', inputValue );
							
							fetch('<?php echo admin_url( 'admin-ajax.php' ) ; ?>', {
								method: 'POST', // or 'PUT'
								body: dataluq
							})
							.then(response => response.json())
							.then(data => {
								console.log(data);
								let event = new Event("update_checkout");
								document.body.dispatchEvent(event);
								
								}
							
							);

				});

			})
			</script>

before calculate total hook

	add_action('woocommerce_before_calculate_totals', $plugin_public, 'luq_woocommerce_before_calculate_totals', 10);

public function luq_woocommerce_before_calculate_totals( $cart_object ) {

		if( !isset($_SESSION) ) session_start();
		
		if($_REQUEST['lprice']){
			$_SESSION['amount_number'] = $_REQUEST['lprice'];
		}
		
		if(isset($_SESSION['amount_number']) ){
			foreach ( $cart_object->get_cart() as $hash => $value ) {
				// check if the product is in a specific category and check if its ID isn't 12345
				if($value['product_id'] == 726 ) {
					$value['data']->set_price(intval($_SESSION['amount_number']));
				}
			}
		}
		
		 
		 
	}