You can add a video either to your template (the video will then appear on all the cards linked to the template if you have the power to manage several cards) or to a card.
In the template or the card, go to "Content" > "News".
Then click on "+ create a news item below or above the map".
Then click on the video logo
You will then need to add the link / url to your video in the area provided (Please note that we do not host videos, you must upload your videos to an online video service such as Youtube, Vimeo, etc.).
You can also enter a start and end date. If you do not set a date, the video will remain visible at all times.
TO FINISH DON'T FORGET TO CLICK ON THE SAVE BUTTON to confirm your changes.

Check that your video is on your business card(s). If this is not the case, check that the url of your video is in the correct format, for example for YouTube : https://youtube.com/watch?v=xxx