Hello @avijitpalit3
Thanks for reaching out about your video indexing report. No thumbnail URL provided means there’s no thumbnail image specified for the video, and Google could not generate one for you.?
You should provide a link to a thumbnail?for your video using structured data, a sitemap, or an mRSS file. If you provided a thumbnail URL using structured data and got this error, check that you are not defining a different thumbnail URL for the same video in an HTML tag. You should provide the same title, thumbnail URL, and video URL in all sources (sitemap, HTML tags, meta tags, and structured data) that describe the same video on the same page.
You can resolve this error by providing a high-quality thumbnail. You can view the ways to do this?here. Moreover, we also provide a premium add-on plugin that allows you to configure the video thumbnail, among other features. You can read more about the Video SEO plugin here:?https://yoast.com/wordpress/plugins/video-seo/.