Trying to edit the "Patient Testimonials" section with Elementor, you'll notice that it's a Tabs element and each tab contains an Elementor template:

The easiest way to access these templates is to mouse-hover the "Edit with Elementor" link on the top Toolbar and locate the sections' templates: 

Clicking on each of them will redirect you to the template's content: 

You can also access the templates from Dashboard > Templates > Saved Templates > Section:

Make your customizations, following this guide: Guide to Vamtam Elementor Builder