Linking to anchors on the page via the Standard navigation bar is not currently supported, as it is designed to list pages as links rather than internal anchor points.
However, there is a dropzone in the Standard navigation where you can place buttons or text elements and manually link them to anchor points on the page.
If that’s not an option, the best approach would be to create a custom set of links or buttons using the built-in components. A Flex with Buttons could work well for this setup!