It is indeed possible of course. Create a Div and set the background image to your video. Add some custom CSS targeting the Div’s background image; background-attachment: fixed;
Setting your bg image as fixed will achieve the parallax effect. Add another Div within that Div and set it to position absolute. Top: 0; Then add you desired heading within that Div. Here is a how-to;
Happy it worked out for you
Cwicly is a labyrinth of capabilities, very powerful.
If I can’t manage it in the Cwicly UI I just write it in Sass within Cwicly.