The boring head is threaded onto the arbor with a normal right hand thread, so it can only be used with a normal clockwise spindle direction (when viewed from above). That means the boring bar will need to be a RH tool, so that the insert sticks out and travels in the correct direction.

It's difficult to explain this clearly in words but here's an example of how it's used and what the bars look like. I've not visited this site before but it seems to illustrate typical practice:
https://johnfsworkshop.org/home/proc...e-boring-head/

Hope this helps.