Meal maker help what am I messing up on

Everything was running fine until the last line. What is going on?
it says get random course is not defined

const menu ={
  _courses : {
    apps:[],
    mains: [],
    desserts: []
  },
  get courses(){
    return {
      apps: this.apps,
      mains: this.mains,
      desserts: this.dessert
      
    }
  },
  get apps (){
    return this._courses.apps;
  },
  set apps(apps){
      this._courses.apps = apps;
  },
  get mains(){
    return this._courses.mains;
  },
  set mains(main){
    return this._courses.mains = main;
  },
  get desserts(){
    return this._courses.desserts;
  },
  set desserts(dessert){
    return this._courses.desserts = dessert;
  },

  addDishToCourse(courseName,dishName,price){
    const dish = {
      name: dishName,
      dishPrice: price,
    };
  return this._courses[courseName].push(dish)
  },
  getRandomDishFromCourse(courseName){
    const dish = this._courses[courseName];
    const randomIndex = Math.floor(math.Random * dish.length);
  return dish[randomIndex];  
  },
generateRandomMeal(){
  const apps = getRandomDishFromCourse('apps');
  const main = getRandomDishFromCourse('mains') ;
  const dessert = getRandomDishFromCourse('desserts')
  const totalPrice = apps.price + main.price + dessert.price;

  return `Your meal is ${apps.name}, ${mains.name},${dessert.name} The price is $${totalPrice}.`;
}
};

menu.addDishToCourse('apps','garlic twists',3);
menu.addDishToCourse('apps','meatballs',6.90);
menu.addDishToCourse('apps','cheese sticks',3);

menu.addDishToCourse('mains','cheese pizza',10);
menu.addDishToCourse('mains','pepperoni pizza',10);
menu.addDishToCourse('mains','sausage pizza',10);
menu.addDishToCourse('mains','spaghetti marinara',7);
menu.addDishToCourse('mains','bolognese',7);

menu.addDishToCourse('desserts','chocolate cake',5);
menu.addDishToCourse('desserts','lava cake a la mode',6);
menu.addDishToCourse('desserts','milkshake',4); 

let meal = menu.generateRandomMeal();


the const in generateRandomMeal need “this” keyword to refer back to what you want from your code above.

for example this.getRandomDishFromCourse(‘apps’).
there is also a word or two that need to be capitalized