React js mutate object via reducer. How to?

My code

I have an object gambits like this

gambits: {
     0: {top: 40, left: 231, title: "Card G_0"}
     1: {top: 110, left: 134, title: "Card G_1"}
     2: {top: 46, left: 109, title: "Card G_2"}
     3: {top: 75, left: 212, title: "Card G_3"}
     4: {top: 81, left: 139, title: "Card G_4"}
     5: {top: 64, left: 267, title: "Card G_5"}
     6: {top: 77, left: 109, title: "Card G_6"}
}

I have a functions which call the useReducer Context via dispatch.

 const moveGambitDest = (id, left, top) => {
    return dispatch({ type: MOVE_GAMBIT_TO_DEST, left, top, id });
  };

Inside the reducer i want to update the left and top value passed via dispatch.

export default (state, action) => {
  switch (action.type) {
    case MOVE_GAMBIT_TO_DEST:
      return {
        ...state,
        gambits: { ...state.gambits } // how to mutate the object ?
      };
    default:
      return state;
  }
  1. I do i mutate the object gambits inside the above reducer ? .
  2. How do i pass multiple values as payload (id, top ,left) please check my moveGambitDest function

Thanks.