Trying to edit the "Your IT Challenges" Carousel with Elementor, you'll notice that each slide item contains an Elementor template:
The easiest way to access these templates is to mouse-hover the "Edit with Elementor" link on the top Toolbar, locate and click on Slider 1 - H. IT Sevices, Slider 2 - H. IT Sevices, Slider 3 - H. IT Sevices and Slider 4 - H. IT Sevices sections:
Clicking on each will redirect you to the template's content:
You can also access the templates from Dashboard > Templates > Saved Templates:
Make your customizations following these guides:
https://elementor.com/help/testimonial-carousel-pro/
Guide to Vamtam Elementor Builder