Default is the 2.5mm jack, not the handset jack.
The steps below have to be done from system programming, if you don't know how to access system programming you have to get technical assistance. Passwords to access installer level programming can't be given out on the board.
In Flash 50 page 2 button 18, you can change it to the handset jack. You still have to option the speaker for headset use and it will still toggle with 634
Flash 50 page 2 button 4 in system programing. To enable headset use in speaker options.
The 634 will NOT work until this is done as explained in a previous post, please review the post. This is what makes the on/off button activate the headset or speaker.
After programming 634 to activate headset 634 again to put it back to speaker, or you can program a button to toggle it.
