can't you change

 {
        path: "journalentry",
        element: <JournalEntry onSave={Storage}/>
    },

to

{
    path: "journalentry",
    element: <Storage/>  // Render Storage component directly
}

because inside Storage Component, JournalEntry is rendered.

According to your code,

Storage is the parent component and it manage state and also has the save method. JournalEntry is a child component inside it