Yes, and I'm also getting a 500 error, but it may be for a different reason. It would be helpful to post the "detailed error information" that you see in your browser, especially the error code (not 500). The error code I get is 0xc0000005, an access violation, which apparently indicates a memory error that the operating system doesn't know how to deal with. I'm still looking for a solution.
I see that you're using Pro's default conda environment. I assume you've installed wfastcgi there, although Esri apparently discourages changing anything in that environment.
Hi Jason Wise, thank you for the reply . The conda environment is a clone using a different file path. I have resolved the issue since then have gotten arcpy and arcgis python api to run in flask on iis. It was just making sure the permissions are correctly set in the identity pool in IIS (Plus a whole lot of workaround to get it to work ).