outbound connectivity to external url from our internal server

Trying to go out of our server using an API call to external url , for authentication, we have restriction to go out from GTM/LTM , I want to configure an irule for the same , any suggestions

This is outbound connectivity for f5, the traffic will be initiated from the server to external public url. from server the external URL are called through DNS request thru GTM

So traffic flow is internal server --->DNS-->F5 GTM--> URL hosted in the internet