Missing 'Open the administration' button when running locally

General
2

This can help
check inside config/server.js
add the following inside

module.exports = ({ env }) => ({
....

admin: {
    auth: {
      url: env('ADMIN_URL'),
      secret: env('ADMIN_JWT_SECRET'),
    },
  },

be sure to add inside your .env file the variables: ADMIN_URL = "/admin" and a ADMIN_JWT_SECRET = "jwt secret goes here"