Error in Browser console

Getting this error. Application runs fine but my redux store is not working.

Store.js

import { configureStore } from "@reduxjs/toolkit";
import merchantSlice from "./redux-slices/merchantSlice";

const store = configureStore({
    reducer: {
        merchant: merchantSlice.reducer,
    }
})

export default store;

merchantSlice.js

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

const initialState = {
    merchant: "abcd",
    token: null,
}

const merchantSlice = createSlice({
    name: "merchant",
    initialState: initialState,
    reducers: {
        setMerchant(state, action){
            state.merchant = action.payload;
        },
        setToken(state, action){
            state.token = action.payload;
        },
        logOutMerchant(state){
            state.merchant = null;
            state.token = null;
        },
    }
})

export const { setMerchant, setToken, logOutMerchant } = merchantSlice.actions;
export default merchantSlice.reducer;

I am trying to create the redux store for my application.