There are more actions than fit in a row — more than three row actions belong in a menu, not side by side.
The actions belong to one record or one screen and should be offered together, so they can be compared.
One of them is irreversible: it gets the danger tone and a separator above it, so nobody clicks it by accident.

When not to use it

A VALUE is being chosen, not an action — that is IngotSelect or IngotSegmented. A menu triggers, it does not select.
Navigation between the application's sections — that is IngotMegaMenu in the top bar.
Two or three actions that fit side by side. A menu that has to be opened to show two items is one step too many.

Properties

open: boolean — Controlled, like the popover underneath.
anchorRef: RefObject<HTMLElement | null> — The button that opens the menu. Focus returns to it after a selection.
onClose: () => void — Called by a selection, by Escape, by Tab and by a click outside.
items: readonly IngotMenuItem[] — The items in the order they are read.
label: string — Translated name of the menu — what a screen reader announces on open.
placement: IngotPlacement — Defaults to bottom-end: a menu usually hangs from the right edge of its button.
className: string — Layout only — typically the width.
testId: string — An anchor for tests.