I would like to create a reducer that updates the value of a variable.

So far I have this but I don't know which code to use to update the value:

    import { createSlice } from '@reduxjs/toolkit';

    const initialStateValue = {
        value: ''
    }

    const benutzerSlice = createSlice({
        name: 'user',
        initialState: initialStateValue,
        reducers: {
            changeValue: (state = initialStateValue) => {
               state.value;
            },
        }
    });

    export const {changeValue} = userSlice.actions;
    export default userSlice.reducer;