I have this React code in return:

I would fetch and store key value on option, when select is changing.

<select
  className={"select_1"}
  onChange={(event: React.ChangeEvent<HTMLSelectElement>) => {
    let startPaymentIn2 = { ...startPaymentIn };
    var selectedIndex = event.target.options.selectedIndex;
    startPaymentIn2["pricingOptionId"] = event.target.options[
      selectedIndex
    ].getAttribute("key");
    setStartPaymentIn(startPaymentIn2);
  }}
>
  {Object.entries(buyTicketData?.pricingOptions).map(([key, value]) => (
    <option key={key}>{value.name}</option>
  ))}
</select>;

For some reason getAttribute("key"); return null, why?