There should be a feed on the C-Pap machine itself where you can hook the O2 hose. Look at the machine,m and youj should see something sticking out about an inch. That's where the O2 gets fed in.

I have a trilogy machine, but its has same tubing. Mine has a short adapter you put between tubing and mask and it has a port for O2 tubing, check with O2 company or cpap provider

My tubing is connected directly to my cpap and comes through the pillow when machine is on

My machine cpap has a nipple connector that is seperate from machine , i got from oxy co it slips onto intake mount on cpap where hose goes in and then hose is pushed on that so i can run my o2 at 3 litres

Mine came with a fitting that goes in the mask hose and the o2 hooks on there.