To create your own theme header and footer in Elementor Page Builder please follow these steps:

1. Install the Elementor Header & Footer Builder plugin
2. Go to Appearance → Elementor Header & Footer Builder
3. Click “Add New” at the top
4. Select header or footer at the “Type of Template “setting
5. Click “Edit with Elementor” to start building (or import a prebuilt layout) your own theme header and/or footer