Using Headers and Footers from Template Kits
In the Pro Template Kit demos, you should have noticed that there are Headers and Footers included in the layout. As a Style Kits Pro user, you can easily use them along with any template in the kit.
In every Template Kit, you will find a utility template, usually named "Layout". If you import this template, you will find a simple layout, along with the sections for the Header and footer. Copy the Header section, and paste it in a Header Template of the Elementor Theme Builder. Likewise for the footer, copy the available Footer sections from the Layout template, and paste it inside a Footer template.
For more information on creating Header and Footer templates with Elementor Pro, feel free to go through the following articles from the official documentation: