This function is to add an item in the admin panel's nav bar.
| Parameter | Details |
|---|---|
| $page_title | (string) The text to be displayed in the title tags of the page when the menu is selected. |
| $menu_title | (string) The text to be used for the menu. |
| $capability | (string) The capability required for this menu to be displayed to the user. |
| $menu_slug | (string) The slug name to refer to this menu by (should be unique for this menu). |
| $function | (callable) (optional) The function to be called to output the content for this page. |
| $icon_url | (string) (optional) The URL to the icon to be used for this menu. |
| $position | (int) (optional) The position in the menu order this one should appear. |
Here is a list of the default positions (for $position)