I want to insert in federated db TABLE1, when records get inserted into
DSY.TABLEA table.

CREATE TRIGGER DSY.TRIGA AFTER INSERT ON DSY.TABLEA
REFERENCING NEW AS TriggeredRow
FOR EACH ROW MODE DB2SQL
INSERT INTO FEDSERV.TABLE1
(LOG_TIMESTAMP, USER_NAME)
VALUES (CURRENT TIMESTAMP, TriggeredRow.NAME);

SQL30090N  Operation invalid for application execution environment.
Reason
code = "22".  LINE NUMBER=2.  SQLSTATE=25000

So then I added PROCEDURE1, but this did not help:
CREATE PROCEDURE DB2ADMIN.PROCEDURE1 ( IN NAME VARCHAR(50) )
P1: BEGIN
               INSERT INTO FEDSERV.TABLE1  (LOG_TIMESTAMP, USER_NAME)
VALUES (CURRENT TIMESTAMP, NAME);
END P1

CREATE TRIGGER DSY.TRIGA AFTER INSERT ON DSY.TABLEA
REFERENCING NEW AS TriggeredRow
CALL DB2ADMIN.PROCEDURE1(TriggeredRow.NAME);

SQL0723N  An error occurred in a triggered SQL statement in trigger
"DSY.TRIGA".  Information returned for the error includes SQLCODE
"-20136",  SQLSTATE "55047" and message tokens
"DB2ADMIN.PROCEDURE1|SQL051117152646510".