I use Record<string, MyUser> and the key of the object is a number. Why I get no error because I set Record<string>?

interface MyUser {
  name: string;
  id: number;
  email?: string;
}

const user = (users: MyUser[]): Record<string, MyUser> => {
  return users.reduce((a, v) => {
    return {
      ...a,
      [v.id]: v
    }
  }, {});
};
 
  const find = () => {
    console.log(user([{
      id: 2,
      name: 'Hosa',
      email: 'saas@asa.com'
    }, { id: 2, name: 'Hsasa', email: 'ASDSDA@asa.da' }]))
  };