How do I escape special characters when using Concat as a node value?

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I want to use the monitoring API detailed here: https://docs.oracle.com/en/cloud/paas/integration-cloud/rest-api/op-ic-api-integration-v1-monitoring-instances-get.html

The documentation shows the query string needs to be formatted like this:

{primaryValue : 'filea' , secondaryValue : 'abcd' , tertiaryValue : 'defg'}

My GET request looks like this in postman:

https://<oururl>/ic/api/integration/v1/monitoring/instances?q={timewindow : '1h', primaryValue:'XYZ44325'}

I can't figure out how to set the value in OIC correctly as it is a dynamic string (see attached) because I need to include special characters like a comma in between values, which OIC does not like as the Concat function itself recognises a comma as a special value.