Add an internal page link in content header in a button

Hello,

I need to add a button in a content header with a link to an internal page. I add the code on the area: Additional Post / Page Options under: Extra (displays under the Subtitle in the content header).

I use this code:

Button name

but the link invokes an internal 404 error. The link address is repeating the name of the page I am placing the button on and then after that the page I specified. I have tried different ways of formatting the link but it does not work.

The code works fine on a regular page but not in the content header.

How do I need to write the code?

Thanks a lot!
Elisabeth