EQAPS3020E The server failed to complete the request because the specified CICS region is not available.

Explanation
CICS region set up with TCPIPSERVICE:

Debug Profile Service API acts as a client, routing HTTP requests to the DTCN API running on the
target CICS region. However, Debug Profile Service API was not able to reach the target CICS
region.

CICS region set up with EXCI:

Debug Profile Service API interfaces directly with the CICS DTCN Repository Manager to manage
debug profile running on the target CICS region, bypassing the DTCN API altogether. However, Debug
Profile Service API was not able to reach the target CICS region.

System action
Connection to target CICS region failed. 

User response
Ensure that the CICS region is online, and verify that the CICS resources are defined and
installed as described in Defining the CICS TCPIPSERVICE resource or Defining the CICS EXCI CONNECTION and SESSIONS resources.