I enter kermit:superSecret as credentials, see a flash of the admin panel,
And get this:
2019-10-28 10:46:55.381 WARN 20000 — [io-8080-exec-10] o.glassfish.jersey.servlet.WebComponent : A servlet request to the URI http://localhost:8080/api/admin/auth/user/default/login/welcome contains form parameters in the request body but the request body has been consumed by the servlet or a servlet filter accessing the request parameters. Only resource methods using @FormParam will work as expected. Resource methods consuming the request body by other means will not work as expected.