In the 10Web Builder, there are two ways you can add HTML tags to your header/footer.
Adding Custom HTML to Header/Footer of Entire Website
Click on the hamburger menu and go to Site Settings.
Click on the Custom CSS button and enter the custom CSS or HTML for header/footer in their appropriate fields.
Adding Custom HTML to Header/Footer of a Specific Page
Click on the Settings icon then go to the Advanced tab.
Open the HTML dropdown menu and enter the custom HTML for header/footer of that specific page in their appropriate fields.