code: public BackchannelAuthenticationIssueResponse callBackchannelAuthenticationIssue(String ticket)
      {
          // Create a request for /api/backchannel/authentication/issue API.
          BackchannelAuthenticationIssueRequest request = new BackchannelAuthenticationIssueRequest()
              .setTicket(ticket)
              ;
  
          try
          {
              // Call Authlete's /api/backchannel/authentication/issue API.
              return mApi.backchannelAuthenticationIssue(request);
          }
          catch (AuthleteApiException e)
          {
              // The API call failed.
              throw apiFailure("/api/backchannel/authentication/issue", e);
          }
      }
docs: Call Authlete's {@code /api/backchannel/authentication/issue} API.