If you want to display “Breadcrumbs Border” and “Underline on Links” in single page for this follow below steps:
You will find this option in the WordPress Dashboard -> Navigate to AMP option panel -> Design -> Single -> Enable “Advanced Single Options” option and then click on the “Save Changes” button.

Scroll down a little to see this option

- Advanced Single Options: Enable this option two option will be shown Breadcrumbs Border and Underline on Links.
- Breadcrumbs Border: Once you enable this option below the Breadcrumbs Border will be displayed.
- Underline on Links: Once you enable this option Underline display on Links and then click on the “Save Changes” button.
The output of the Breadcrumbs Border and Underline on Links in single page

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.