How to pass values (not by reference) to an array in javascript

Question

I am having more issues than what i would guess with creating an array and updating its values, i create 4 positions array, and somehow, if i try to update the 1st position the second updates two, same with 3 and 4. the values in both paris are the same and taken from a variable.

for (let index = 0; index < recursos.length; index++) {
    let recurso = recursos[index];
    cantidad = parseInt(recurso.cantidad);
    //frm.recursosCrear(recurso);
    for (let index2 = 0; index2 < cantidad; index2++) {
        const copia = recurso;
        frm.recursos2.push(copia);                               
    }
}
frm.recursos2[1]["inicio"]= "9999";
console.log(frm.recursos2);

In this case frm.recursos in pos 0 and 1 both end up with an "inicio" of 9999 even when i only asked for the pos 1

recursos cointains arrays in this case 2 arrays, one that has the info "cars" and the amount of cars "2", and anotherone with "people" and the amount of people "2", the idea is that the final array has 4 positions, 2 cars and 2 persons