Hello YeshwanthGowda18001269 ,
The return template response to requestor assertion has an option to return the response to front end immediately.
But, this option won't stop the execution of the policy, ie. all the assertions after this assertion will be executed even the response is sent to the front end.
I believe that how you make the async call, return template response to front end immediately and then route via http(s) to the backend service.
Regards,
Mark