Blockstack

<script src="https://unpkg.com/blockstack@19.2.1/dist/blockstack.js" integrity="sha384-+qYCYoUGzsMLAzHm80c4DyhbWgHBBb2N0RFqsg7Lws5ljtBtj/IwpgxZkiR7j7lp" crossorigin="anonymous"></script>
<button id="signin-button">Sign in with Blockstack </button>

<script>
const appConfig = new blockstack.AppConfig();
  const userSession = new blockstack.UserSession({ appConfig: appConfig });
 document.getElementById('signin-button').addEventListener('click', function() {
   userSession.redirectToSignIn();
 });
if (userSession.isUserSignedIn()) {
 document.getElementById('signin-button').remove();
storePref();
 } else if (userSession.isSignInPending()) {
   userSession.handlePendingSignIn()
   .then(() => {
console.log("Signed in by pending");
 document.getElementById('signin-button').remove();
storePref();
   })
 }
 function storePref()
{
console.log("Logged in")
}
 
</script>