Can’t get dynamic Gutenberg block to render on the frontend

I tried everything I found online. The backend appears, including dynamic segments (withSelect, etc). But the simplest ‘render-callback’ doesn’t appear on the frontend.

plugin.php

/**
 * Plugin Name: My Dynamic Block
 */

function my_plugin_render_dynamic_block( ) {
    return '<h1>Sample Block</h1>';
}

function register_dynamic_block() {
    wp_register_script(
        'dynamic-block',
        plugins_url( '/dist/block.js ', __FILE__),
        array( 'wp-blocks', 'wp-element', 'wp-editor' ),
        filemtime( plugin_dir_path( __FILE__ ) . 'dist/block.js' )
    );

    register_block_type(
        'my-plugin/dynamic-block',
        [
            'editor_script' => 'dynamic-block',
            'render_callback' => 'my_plugin_render_dynamic_block',
        ]
    );
}
add_action('init', 'register_dynamic_block');

block.js

const { __ } = wp.i18n;
const { registerBlockType } = wp.blocks;

registerBlockType( 'my-plugin/dynamic-block', {
    title: 'My Dynamic Block',
    icon: 'megaphone',
    category: 'widgets',

    edit({attributes}) {
        return (
            <div>Content</div>
        );
    },

    save() {
        return null;
    },
} );

Since you’re making a dynamic block you don’t need to register the block in JavaScript. Take a look at the Latest Posts block in Core to see how they do it.