Hello,
Thanks for the screen shot. That’s actually the management interface for a new or existing Shortcode in VikRentCar. That’s not a page to manage widgets/blocks, which should be rather managed through your page-builder plugin, or through the native Gutenberg or any other plugin.
Your screen shot shows that you’re creating a new Shortcode of type “Search Form”, which is correct, and once saved, you can add it to a WordPress page of your website. As we said, the same exact operation for adding a new page with a Shortcode of VikRentCar could be performed through Gutenberg by selecting the apposite block type “VikRentCar Shortcode”. Anyway, your procedure is the classic one, and so it will work just fine.
Once you will have a working Shortcode connected to a page/post, you will be able to select it from the settings of the widget/block “Search Form”, which is not a page, but rather a block that you can publish on any section of your front-end pages, usually in the home page of your site. Moreover, please notice that Shortcodes should not be used in the home page of your site, or the WordPress routing functions for the booking process may not work properly. This is why widgets/blocks are usually published in the home page and connected to a Shortcode.