near-login

step1.ts

import { keyStores, Near, utils, WalletConnection } from "near-api-js";

step2.ts

export const CONTRACT_ID = "YOUR_CONTRACT_ID.testnet";

step3.ts

export const near = new Near({
 networkId: "testnet",
 keyStore: new keyStores.BrowserLocalStorageKeyStore(),
 nodeUrl: "https://rpc.testnet.near.org",
 walletUrl: "https://wallet.testnet.near.org",
});

step4.ts

export const wallet = new WalletConnection(near, "guest-book");

step5.ts

const accountId = wallet.getAccountId();

const signIn = () => {
      if (accountId) {
        wallet.signOut();
        window.location.reload();
      } else {
        wallet.requestSignIn(CONTRACT_ID);
      }
    };