Is there any way to see all requests that hit the /ic/api/* server?

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So we have a vendor who developed a mobile application that calls one of our integrations.  The app works sporadically,  In other words, if I execute the call to our integration from the mobile application it will sometimes show in the monitoring / tracking page and sometimes it wont show in there and wont trigger the integration.  I strongly believe this is an issue on their end (possibly if an invalid json payload).  However, I would like to see the payloads that attempting to hit our integration and failing.  What logging settings and what logging file should I use?  I