[#10786] - Unable to execute reports using Keycloak SSO with visualize.js

I am trying to execute a report with visualize.js and using external Keycloak SSO for authentication. I retrieved an access token from SSO server and need to pass the token in the header. The Visualize.js documentation says that we can add the header object but while adding a header it gives me an error saying "header" is not a valid JSON syntax.

I am using below syntax for making the request
visualize({
server:"http://localhost:8080/jasperserver-pro/",
auth : {
token: keycloak.token
headers:{Authorization:"Bearer"}
}
}, function (v){
console.log("LOGGED IN ");
}, function(err){
console.log(err.message);
}
);