What database is this project connected to?

[NVJKKartik]

I saw in your code, that you are using your own REST api hosted on railway

`export async function addMoneyDB(uid, amount) {
  const options = {
    method: 'POST',
    url: `https://papercryptoapi.up.railway.app/add_balance`,
    params: {
      uid,
      amount
    },
  };

  try {
    const response = await axios.request(options);

    return response.data;
  } catch (error) {
    console.error(error);
  }
}`

Can you please tell me what database are you using and how did you setup this API?
Thanks in advance