You have to join the security information from TREX and from the application using TREX. You do this in the following way:
Export and Import of the Application Certificate
You export the application certificate which is stored inside the key store on application side and import this certificate on TREX side.
Export and Import of TREX Certificates
You export the TREX certificate which is stored inside the key store on TREX side and import this certificate on application side.