Menu Item Settings > General > Disable Link
How to remove the link from a menu item
By default, the WordPress menu system assumes every menu item is an anchor with a valid href (a link). However, sometimes you just want a pure display item that isn’t interactive, in which case the item should no longer display an anchor.
The Disable Link setting will change your menu item’s <a> tag to a <span> tag, removing the link and just leaving the text. Hovering the item will show the default cursor. Clicking the item will not follow the link.
User interactions for disabled links
If you are using the Hover trigger, clicking will do nothing. If you’re using the Click trigger, clicking will toggle the submenu open and closed (if there is a dropdown submenu)