Use the Custom link variation of the Navigation link to create a custom link.

Screenshot

Example

There should be two custom links: Custom link 1 and Custom link 2.

Notes

• The Custom Link is expected to be used in the Navigation – core/navigation block.
• You can programmatically create a Custom link.
• You can’t explicitely add a Custom link block into a post/page or even Navigation block.
• They’re created automatically, so it seems.

HTML for a custom link