The edit code saves the heading value in meta. How do I save it in the save function? 

The render_callback is as below. I tried passing "render": "file: path-to/php.php" in block.json but it doesn't work. 

    function register_latest_post_item() {
        register_block_type("create-block/items", [ "render_callback" => "render_latest_post_item"
        ]);
    }
    add_action("plugins_loaded", "register_latest_post_property_item");
    
    function render_latest_post_property_item( $value, $object, $field_name ) {

block.json code

    {
	"$schema": "https://schemas.wp.org/trunk/block.json",
	"apiVersion": 2,
	"name": "create-block/items",
	"version": "0.1.0",
	"title": "Items",
	"category": "widgets",
	"icon": "smiley",
	"description": "Example block scaffolded with Create Block tool.",
	"attributes": {
		"heading": {
			"type": "string",
			"default": ""
		
		}
	},
	"supports": {
		"html": false
	},
	"textdomain": "property",
	"editorScript": "file:./index.js",
	"editorStyle": "file:./index.css",
	"style": "file:./style-index.css",
	"render": "file:../render/render.php"
	}
	


Edit function

    import { __ } from '@wordpress/i18n';
    import { useEntityProp } from "@wordpress/core-data";
    import { useSelect } from "@wordpress/data";
    const {
    	TextControl,

    } = wp.components;


    import { useBlockProps } from '@wordpress/block-editor';

    import './editor.scss';


    export default function Edit(props) {

	const [meta, setMeta] = useEntityProp("postType", "listing", "meta");

	const heading = meta["heading"];

	const onChangeheading = (newValue) => {
		setMeta({ ...meta, heading: newValue });
		
	};
	


	return (
		<div {...useBlockProps()}>
			
			<div>
				<TextControl
					tagName="h1"
					label="title"
					className="card-title"
					value={heading}
					onChange={onChangeheading}
				/>
			</div>
		</div>
	);
    }


index.js


    
    import { registerBlockType } from '@wordpress/blocks';
    import { useBlockProps } from "@wordpress/block-editor";
    import { useSelect } from "@wordpress/data";


    import './style.scss';


    import Edit from './edit';
    import save from './save';
    import metadata from './block.json';



    registerBlockType( metadata.name,   {

	
	edit: Edit,

	save,
	} );