MoHO Skier welcome to irv2 and the Newmar forum.
Go to "FIND" just above you and type in "chair bolts" leave the check mark. Someone asked the same question awhile back and the answer is there. Some chairs maybe mounted differently so could be a different answer but it is there for you just don't know which will be yours. You have seen bolts in ceiling of compartment below chair the other two maybe thru floor outside of compartment.
A Newmar owner as yourself can be a member in Newmar forum which is called KARMA if you want it I will input for you.
Enjoy the forums and post often.