Problem with automation of "get OAuth2 access token"

To Whom Could Help,

I am new to SOAPUi REST testing automation. 

I would like to automate RESTful test suites that need an access token every 300 seconds, from a access server that does NOT have a GUI, it only send a token response after I send the Clien ID, Clien Secret, etc..

I filled out all the necessary fields to get the access token manually from a , it works like a charm, but the "OAuth 2 Advance options" "Refresh Access Token" Automatic setting does not seem to work, I have to get it every time manually.

Do I need to set something else too? 

Do I need a JS/groovy script to get the token? 

Thank you in advance. 

BR,

Zsolt