Every array key must match to the related finisher option name.
For example, the - :ref:`"[Redirect] finisher"<prototypes.prototypeIdentifier.finishersdefinition.redirect>` has the option - :ref:`"pageUid"<prototypes.prototypeIdentifier.finishersdefinition.redirect.options.pageuid>`.
If you want to make the ``pageUid`` overwritable within the ``form plugin``, then an array key ``pageUid`` has to exists within ``prototypes.prototypeIdentifier.finishersDefinition.finisheridentifier.FormEngine.elements``.
The configuration within ``prototypes.prototypeIdentifier.finishersDefinition.Redirect.FormEngine.elements.pageUid`` must follow the TCA syntax.