To begin, navigate to the Toolbar > Edit with Elementor > Footer (the name of the template may be different)
Or go to Templates > Theme Builder > Footer (the name of the template may be different) > Edit with Elementor. Control the footer template's layout, conditions, rules, and styles.
Please check these guides for further information:
Create Footers Using Elementor
Guide to Vamtam Elementor Builder
Next, click on the "Save options" icon and select "Display conditions":
Here, you can add the footer template to whichever post or page.
Please check these guides for further information:
Vamtam Elementor Themes: How to apply different headers/footers to different pages?
Editing the Footer for mobile resolution
When hiding an element and switching to the view it’s hidden on, you will see that this element is “muted” - see the yellow arrows:
This indicates that this element will be hidden on the live site but still enables you to edit it as needed.
You can edit that specific area in the responsive mode that is not hidden. For example, if the element is visible on mobile but hidden on desktop and tablet, you can edit the element in the mobile view.
Switch between Desktop, Mobile, or Tablet views by clicking on the corresponding icons at the bottom of the panel and editing the content dedicated to the corresponding resolution
You can also check this instruction: https://elementor.com/help/mobile-editing/