When testing IOT Enrollment with EST using passcode, the enrollments fail.
You can verify the error using Postman.
The request fails with the below error:
"message": "Invalid username or passcode"
Once the passcode is generated within IOT Manager, it needs to be converted to Base64 first (Example: http://www.utilities-online.info/base64/#.XyUHCvgzbyg) to do the conversion, and then add the passcode to the header in Postman.
Run the EST enrollment again and the enrollments will succeed.
If you run into issues and need assistance, please Contact DigiCert PKI Support