Hello,
WoodMart Sliders currently support Background Image only. In case you want to use Background video for the slides, then you can use Revolution Slider instead.
Additionally, You can add the video in the elementor container background, Try to use the theme template library and import the premade template:
Screenshot for clarification:
https://ibb.co/RNPFDYs
For more details follow this guide:
https://xtemos.com/docs-topic/templates-library/
Best Regards
.
