openID credential redirect

I have a service configured in kong for the URL :
with a route /svj
We have openid integration as well, and I make below call to kong with clientid and secret

When I look at the application log, I can see the below entry in application log, - - [24/Jul/2019:14:19:03 +0000] “GET /service/json?grant_type=client_credentials&client_id=XYZ-abc&client_secret=hsadfsa234h1x HTTP/1.1” 400 705 “-” “PostmanRuntime/7.15.2”

My application returns 400 to the above request because its designed to handle only /service/json not /service/json?grant_type=client_credentials&client_id=XYZ-abc&client_secret=hsadfsa234h1x

Here is the log entry of a successful call when i hit the endpoint directly - - [24/Jul/2019:14:27:31 +0000] “GET /service/json HTTP/1.1” 200 4411 “-” "

How can I stop Kong forwarding client_credentials to my application ?