The Unused Input Parameter error is issued in the following situation:
(<parameter name>) is not used by (<method name>) REST API method. Either use it in the (<method name>) URL path, change the (<parameter name>) Send In property, or delete it: you have an input parameter in a REST API method's list, but it's not part of the URL.
Clicking the symbol will take you directly to the REST API method's input parameter where the problem was detected. Follow the instructions in the error message to resolve it.
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