actions-imp.ts

const store = createStore<StoreModel>({
  todos: {
    items: ["Install easy-peasy", "Build app", "profit"],
    // 👇
    add: (state, payload) => {
      state.items.push(payload);
    }
  },
  notification: {
    msg: "",
    // 👇
    set: (state, payload) => {
      state.msg = payload;
    }
  }
});