After doing some logical thinking, I was able to find it myself. It is under the folder: /etc/mysql/mysql.conf.d which holds global options/configurations.
File Name: mysqld.cnf
I then proceeded with adding federated to the below info:
[mysqld]
#
# * Basic Settings
#
user = mysql
# pid-file = /var/run/mysqld/mysqld.pid
# socket = /var/run/mysqld/mysqld.sock
# port = 3306
# datadir = /var/lib/mysql
federated