Admin login fails with 401

Questions and Answers
3

Have you recently migrated from 3.0.x?

Can you check if you have JWT key declared inside the /config/server.js and if you declared the ADMIN_JWT_SECRET in env.

module.exports = ({ env }) => ({
  // ...
  admin: {
    auth: {
      secret: env('ADMIN_JWT_SECRET'),
    },
  },
});`