Every @pindoba/react-* package supports React 18.3 and React 19. They all declare react: ^18.3.1 || ^19.0.0 as a peer dependency, and the same component code runs on both.
When a component exposes its DOM node through ref (Button, Card, Dialog, Table, InputField and others), that component is a forwardRef component, so <Button ref={buttonRef}> binds on React 18 as well as React 19. The Props table on each component page says which element the ref points at.
A component you pass in yourself has to forward the ref too. For example, a router adapter given to Navigation’s linkComponent must forward ref to its <a>. React 19 passes ref as an ordinary prop. React 18 only hands it to a forwardRef component, so wrap your adapter in forwardRef to support both versions (see Navigation’s router integration).