This is the 17125th most frequent Turkish word.
çubuğuna
"To its/her/his stick/rod."
The word 'çubuğuna' is used here in the dative case to indicate the object (stick) to which the pen is being attached.
Kalemi çubuğuna bağladım.
I attached the pen to the stick.
In this sentence, 'çubuğuna' specifies the flagpole (stick) and conveys possession by the flag.
Bayrak çubuğuna ayak basma!
Do not step on the flag pole!
Here, 'çubuğuna' is used to denote the television stick being referred to as the place for attaching the antenna.