Hello,

If you are using the WoodMart Slider, then please navigate to the Dashboard > Slides > Sliders > there edit the Slider that you are using on your Site > under the edit area of the Slider you will get to see the option of defining Height on Desktop, Tablet and Mobile: https://snipboard.io/7YTDRJ.jpg

Further, you can check out these guides from Documentation related to Sliders:
https://xtemos.com/docs-topic/how-to-create-a-slider/
https://xtemos.com/docs-topic/how-to-add-slides-to-the-slider/

Hope this helps !

Best Regards