You can embed a YouTube video directly into a Lucidpress document. The document can be played within a published document. Please note that it will not play within an email, PDF, or image.
Click the 'other' (videos/buttons) tab in the left content pane and then select the YouTube logo. Drag and drop it into the canvas. Once you have added the video, you can change the link in the context pane under video > video URL. This can be your personal YouTube video, or any other YouTube video link you find on the web.
Once you have published your document, access the published link and click the "play button".