language-togglein the top right of the interactive in alignment with the
Homebutton (if present).
language-toggleshould be present on most, if not all, pages. An exception to this convention might be on a fullscreen Gallery or Image Zoom page. Using the component on such a page would detract from the fullscreen design. These pages are likely to be nested within a page on which the toggle was present.
You might also be interested in the Gloss component (inserting definitions of words into paragraph tet) and UI control names (Māori and English names for UI controls).
If more langugages are required, other options might need to be explored to avoid cluttering the interface.