Custom Header for All Pages
For create Custom Header for All Pages, you need before add new HTML-Blocks (for Desktop and Tablet & Mobile).
You can access it from the left-hand menu from Dashboard: HTML-Blocks.
If you add/edit HTML-Block in Elementor you can add our widgets: Page Title, Favorites Button, Header Button, Breadcrumbs, Desktop Menu and Mobile Menu.
After complete creating HTML-Block, you must navigate to WP Customize Panel → Header & Menu → General and select HTML-Block in Custom Header and for Tablet & Mobile.
Custom Header for Specific Page
For create Custom Header for Specific Page, you need before add new HTML-Blocks (for Desktop and Tablet & Mobile).
You can access it from the left-hand menu from Dashboard: HTML-Blocks.
If you add/edit HTML-Block in Elementor you can full control and make custom design of Header and you can apply Comforto Styles (Glass Effect and Blur Effect) from Style Tab in Container.
After complete creating HTML-Block, you must go to Edit Specific Page and select HTML-Block in Page Properties (right side).
Sticky Menu
If you want to create Sticky Menu in HTML-Block, you can just enable Sticky Feature in Style Tab of the Container.
You can set Top Margin after Scroll and Scroll Position (Activate Sticky after Scroll).