Advanced Header Design: By enabling this option you can customize the Header background color, Menu background, width, height, padding, margin, Menu color, Menu Border Color, etc..
You will find this option in the WordPress Dashboard -> Navigate to AMP option panel -> Design -> Header-> Enable Advanced Header Design and then click on the “Save Changes” button.

The Output of the Advanced Header Design

Advanced Footer Design: By enabling this option you can customize the Footer background color, width, height, padding, margin, etc..
You will find this option in the WordPress Dashboard -> Navigate to AMP option panel -> Design -> Footer -> Enable Advanced Footer Design and then click on the “Save Changes” button.

The Output of the Advanced Footer Design

That’s it for this tutorial!
We hope it helped you. If you have any feedback or questions, then please share them in the comments section below.
How do I change the “Sign up free” button text and URL in the header?
Hi Steve Lawrence,
Will you please contact our technical team from here- https://ampforwp.com/support/ they will help you as soon as possible.