Create a custom link browser

use TYPO3\CMS\Core\Page\PageRenderer;
use TYPO3\CMS\Recordlist\Controller\AbstractLinkBrowserController;
use TYPO3Fluid\Fluid\View\ViewInterface;

class GitHubLinkHandler implements LinkHandlerInterface
{
    protected $linkAttributes = ['target', 'title', 'class', 'params', 'rel'];

    protected $linkParts = [];

    protected $view;

    protected $configuration;

    public function __construct(PageRenderer $pageRenderer)
    {
        $this->pageRenderer = $pageRenderer;
    }

    public function initialize(AbstractLinkBrowserController $linkBrowser, $identifier, array $configuration)
    {
        $this->configuration = $configuration;
    }

    public function setView(\TYPO3Fluid\Fluid\View\ViewInterface $view): void
    {
        $this->view = $view;
    }
}

services:
  _defaults:
    autowire: true
    autoconfigure: true
    public: false

  T3docs\Examples\LinkHandler\GitHubLinkHandler:
    public: true
    # The link handler keeps a state and can therefore be no singleton
    shared: false

use Psr\Http\Message\ServerRequestInterface;

class GitHubLinkHandler implements LinkHandlerInterface
{
    public function render(ServerRequestInterface $request): string
    {
        $this->pageRenderer->loadRequireJsModule('TYPO3/CMS/Examples/GitHubLinkHandler');
        $this->view->getRequest()->setControllerExtensionName('examples');
        $this->view->setTemplateRootPaths(['EXT:examples/Resources/Private/Templates/LinkBrowser']);

        $this->view->assign('project', $this->configuration['project'] ?? '');
        $this->view->assign('action', $this->configuration['action'] ?? '');
        $this->view->assign('github', !empty($this->linkParts) ? $this->linkParts['url']['value'] : '');

        $this->view->setTemplate('GitHub');
        return '';
    }
}

/*
 * This file is part of the TYPO3 CMS project.
 *
 * It is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, either version 2
 * of the License, or any later version.
 *
 * For the full copyright and license information, please read the
 * LICENSE.txt file that was distributed with this source code.
 *
 * The TYPO3 project - inspiring people to share!
 */

/**
 * Module: TYPO3/CMS/Examples/GitHubLinkHandler
 * Github issue link interaction
 */
define(['jquery', 'TYPO3/CMS/Recordlist/LinkBrowser'], function($, LinkBrowser) {
	'use strict';

	/**
	 *
	 * @type {{}}
	 * @exports T3docs/Examples/GitHubLinkHandler
	 */
	var GitHubLinkHandler = {};

	$(function() {
		$('#lgithubform').on('submit', function(event) {
			event.preventDefault();

			var value = $(this).find('[name="lgithub"]').val();
			if (value === 'github:') {
				return;
			}
			if (value.indexOf('github:') === 0) {
				value = value.substr(7);
			}
			LinkBrowser.finalizeFunction('github:' + value);
		});
	});

	return GitHubLinkHandler;
});

class GitHubLinkHandler implements LinkHandlerInterface
{
    public function canHandleLink(array $linkParts): bool
    {
        if (!isset($linkParts['type']) || $linkParts['type'] !== 'github') {
            return false;
        }
        $this->linkParts = $linkParts;
        return true;
    }
}