When a JWT is expired, you need to use VincentWebAppClient.redirectToConsentPage to get a new JWT

  import { jwt } from '@lit-protocol/vincent-sdk';

const { decode, isExpired } = jwt;

const decodedVincentJWT = decode(jwt);
const isJWTExpired = isExpired(decodedVincentJWT);

if(!isJWTExpired) {
// User is logged in
} else {
// User needs to get a new JWT
vincentWebAppClient.redirectToConsentPage({redirectUri: window.location.href });
}