Is the video on YouTube? Some other web site? See icon above that says Media. Click on it > Insert media > Enter media URL >
Approved sites, You may insert media from these sources > Apple Music Dailymotion Facebook Flickr Giphy Imgur Liveleak Metacafe Pinterest Reddit SoundCloud Spotify TikTok Tumblr Twitch Twitter Vimeo YouTube
Moved thread to Forum Rules and Features out of E-vehicles General Discussion, where it is more likely to get applicable replies.
To share any file external to the forum (not attached to a post), simply copy the "share" link from the website page the video is uploaded to (youtube, etc) and paste that into your post here on the forum, and that will generate a link interested viewers can click on to go there.
The forum can also automatically handle inline videos from certain places; to use this feature you click the "media" button above where you type your post's text in, and paste the link into the popup that comes up and choose "Continue".