I am new to PAD and am attempting to create a flow that mimics one I have previously created in Power Automate. I have all of the settings the same (URL, method, custom headers, and body) and the flow runs correctly in PA but gives a parsing error in PAD.
{"message": "Could not parse request body into json: Could not parse payload into json: Unexpected character (\'%\' (code 37)): expected a valid value (number, String, array, object, \'true\', \'false\' or \'null\')\n .....
In PAD, I am passing the request body as a variable before I invoke the web service, as shown here:


For comparison, here is my PA flow:

I have also tried to pass the request body directly in the "invoke web service" step instead of as a variable, and I get the same parsing error.
Is there a guide on how the JSON is supposed to be formatted in PAD?