Grails + Spring Security Rest, Make POST Request

Question

I am able to login(/api/login) and have been able to successfully make a GET request. However, I cannot seem to figure out how to make a POST request, and likewise I have not been able to logout (/api/logout).

Controller: (com.example.test)

static allowedMethods = [secret:['POST', 'GET']]
@Secured(['ROLE_ADMIN'])
def secret() {
  render "You have ACCESS!!!"
}

Curl to login (and HTTP response):

curl -v -H "Content-Type: application/json" -X POST -d
  '{"username":"user", "password":"pass"}' 
  http://localhost:8080/restplug/api/login

< HTTP/1.1 200 OK
 {"username":"user","roles":"ROLE_ADMIN"],
 "access_token":"a2d4biqg7oqu0ig4m22pj20qsesva81d",
 "token_type":"Bearer"}

Curl for GET request (example for method secret):

curl -v -i -H "Authorization: Bearer a2d4biqg7oqu0ig4m22pj20qsesva81d" 
   -X GET http://localhost:8080/restplug/TestData/secret

My POST requests always results in being redirected to Login Page (even when I pass the token). Kindly show examples of how to do a post request using curl, or something like a rest client (Postman). Also if possible, show how to logout (/api/logout)

Configuration
grails.plugin.springsecurity.rest.login.active=true grails.plugin.springsecurity.rest.login.endpointUrl='/api/login' grails.plugin.springsecurity.rest.login.failureStatusCode=401 grails.plugin.springsecurity.rest.login.useJsonCredentials=true grails.plugin.springsecurity.rest.login.usernamePropertyName='username' grails.plugin.springsecurity.rest.login.passwordPropertyName='password' grails.plugin.springsecurity.rest.logout.endpointUrl='/api/logout' grails.plugin.springsecurity.rest.token.storage.useGorm = true grails.plugin.springsecurity.rest.token.storage.gorm.tokenDomainClassName="com.example.AuthenticationToken" grails.plugin.springsecurity.rest.token.storage.gorm.tokenValuePropertyName="tokenValue" grails.plugin.springsecurity.rest.token.storage.gorm.usernamePropertyName='username' grails.plugin.springsecurity.rest.login.usernamePropertyName='username' grails.plugin.springsecurity.rest.login.passwordPropertyName='password' grails.plugin.springsecurity.rest.token.generation.useSecureRandom = true

Attempts using POST that failed

Here are some of the what I tried using Curl and postman:

 curl -v -X POST --form "access_token=bdv3de54oglo2i997k1tomvdgptm2ojq"
    http://localhost:8080/restplug/TestData/secret

 curl -v -X POST -H "Content-Type: application/x-www-form-urlencode"
    --form "access_token=bdv3de54oglo2i997k1tomvdgptm2ojq"
    http://localhost:8080/restplug/TestData/secret

And also using postman (attached image):