In the video details of a video you can, among other functions, also create a Custom ID that enables or facilitates an automatic embedding of the video on a website. For the example we have taken "1234", but of course any other combination of letters and numbers is possible. Except for the "/", special characters are also possible.
After pressing "Save changes", your Custom ID will be added to the embed link (the ID is at the end of the link). You can find the embed link by scrolling down from the video details to the player section, where it will be displayed under "E-Mail, Social" and you can simply copy it.