Formik_FieldArray.js

//* Formik props
  const initialValues = {
    decks: [""],    // --- 1️⃣
  };

  const onSubmit = (values, actions) => {
    registerDeck(values.decks);
    getDeck();
    // 입력창 초기화
    actions.resetForm({
      values: {
        decks: [""],
      },
    });
  };

<Formik initialValues={initialValues} onSubmit={onSubmit}>
  <Form>
  <FieldArray name="decks">
   {(fieldArrayProps) => {
      const { push, remove, form } = fieldArrayProps;
        const { decks } = form.values;
          return (
            <div>
              {decks &&
                decks.map((deck, index) => (
                  <Field
                    name={`decks[${index}]`}    {/* --- 2️⃣ */}
                    placeholder="deck name"
                  />
                  <AddIcon onClick={() => push("")} />
                  <RemoveIcon onClick={() => remove(index)} />
                ))}
            </div>
          );
        }}
    </FieldArray>
  </Form>
</Formik>