Simple Example

elementor-oembed-widget/
|
├─ widgets/
|  └─ oembed-widget.php
|
└─ elementor-oembed-widget.php

<?php
/**
 * Plugin Name: Elementor oEmbed Widget
 * Description: Auto embed any embbedable content from external URLs into Elementor.
 * Plugin URI:  https://elementor.com/
 * Version:     1.0.0
 * Author:      Elementor Developer
 * Author URI:  https://developers.elementor.com/
 * Text Domain: elementor-oembed-widget
 *
 * Requires Plugins: elementor
 * Elementor tested up to: 3.25.0
 * Elementor Pro tested up to: 3.25.0
 */

if ( ! defined( 'ABSPATH' ) ) {
    exit; // Exit if accessed directly.
}

/**
 * Register oEmbed Widget.
 *
 * Include widget file and register widget class.
 *
 * @since 1.0.0
 * @param \Elementor\Widgets_Manager $widgets_manager Elementor widgets manager.
 * @return void
 */
function register_oembed_widget( $widgets_manager ) {

    require_once( __DIR__ . '/widgets/oembed-widget.php' );

    $widgets_manager->register( new \Elementor_oEmbed_Widget() );

}
add_action( 'elementor/widgets/register', 'register_oembed_widget' );

<?php
if ( ! defined( 'ABSPATH' ) ) {
    exit; // Exit if accessed directly.
}

/**
 * Elementor oEmbed Widget.
 *
 * Elementor widget that inserts an embbedable content into the page, from any given URL.
 *
 * @since 1.0.0
 */
class Elementor_oEmbed_Widget extends \Elementor\Widget_Base {

    /**
     * Get widget name.
     *
     * Retrieve oEmbed widget name.
     *
     * @since 1.0.0
     * @access public
     * @return string Widget name.
     */
    public function get_name(): string {
        return 'oembed';
    }

    /**
     * Get widget title.
     *
     * Retrieve oEmbed widget title.
     *
     * @since 1.0.0
     * @access public
     * @return string Widget title.
     */
    public function get_title(): string {
        return esc_html__( 'oEmbed', 'elementor-oembed-widget' );
    }

    /**
     * Get widget icon.
     *
     * Retrieve oEmbed widget icon.
     *
     * @since 1.0.0
     * @access public
     * @return string Widget icon.
     */
    public function get_icon(): string {
        return 'eicon-code';
    }

    /**
     * Get widget categories.
     *
     * Retrieve the list of categories the oEmbed widget belongs to.
     *
     * @since 1.0.0
     * @access public
     * @return array Widget categories.
     */
    public function get_categories(): array {
        return [ 'general' ];
    }

    /**
     * Get widget keywords.
     *
     * Retrieve the list of keywords the oEmbed widget belongs to.
     *
     * @since 1.0.0
     * @access public
     * @return array Widget keywords.
     */
    public function get_keywords(): array {
        return [ 'oembed', 'url', 'link' ];
    }

    /**
     * Get custom help URL.
     *
     * Retrieve a URL where the user can get more information about the widget.
     *
     * @since 1.0.0
     * @access public
     * @return string Widget help URL.
     */
    public function get_custom_help_url(): string {
        return 'https://developers.elementor.com/docs/widgets/';
    }

/**
     * Whether the widget requires inner wrapper.
     *
     * Determine whether to optimize the DOM size.
     *
     * @since 1.0.0
     * @access public
     * @return bool Whether to optimize the DOM size.
     */
    public function has_widget_inner_wrapper(): bool {
        return false;
    }

    /**
     * Whether the element returns dynamic content.
     *
     * Determine whether to cache the element output or not.
     *
     * @since 1.0.0
     * @access protected
     * @return bool Whether to cache the element output.
     */
    protected function is_dynamic_content(): bool {
        return false;
    }

    /**
     * Register oEmbed widget controls.
     *
     * Add input fields to allow the user to customize the widget settings.
     *
     * @since 1.0.0
     * @access protected
     */
    protected function register_controls(): void {

        $this->start_controls_section(
            'content_section',
            [
                'label' => esc_html__( 'Content', 'elementor-oembed-widget' ),
                'tab' => \Elementor\Controls_Manager::TAB_CONTENT,
            ]
        );

        $this->add_control(
            'url',
            [
                'label' => esc_html__( 'URL to embed', 'elementor-oembed-widget' ),
                'type' => \Elementor\Controls_Manager::TEXT,
                'input_type' => 'url',
                'placeholder' => esc_html__( 'https://your-link.com', 'elementor-oembed-widget' ),
            ]
        );

        $this->end_controls_section();

    }

    /**
     * Render oEmbed widget output on the frontend.
     *
     * Written in PHP and used to generate the final HTML.
     *
     * @since 1.0.0
     * @access protected
     */
    protected function render(): void {
        $settings = $this->get_settings_for_display();

        if ( empty( $settings['url'] ) ) {
            return;
        }

        $html = wp_oembed_get( $settings['url'] );
        ?>
        <div class="oembed-elementor-widget">
            <?php echo ( $html ) ? $html : $settings['url']; ?>
        </div>
        <?php
    }

}