View attachment 19020 IIRC, HD has been supplying tube and tubless spoked rims for a while; some say since '14 and some say earlier. I don't know from when but do know that there are two type spoked rims; smooth and profile. I have read that smooth rims require tubes and profile rims can go tubeless and I have read visa versa.
again, don't know for sure. However, if an HD spoked rim can be run tubeless, the rim will have a label that identifies the rim as tubeless; see the attached photo which shows that a threaded metal valve stem with a nut does not necessarily guarantee a tube.
If I were the OP, I would check the rim for the tubeless label and if there is no tubeless label, HD sells liners for about $25 to convert a spoked rim that requires a tube to a tubeless rim which is much easier than the processes I have used in the past to seal a spoked rim. A front flat with a tubed tire will result in a call for a tow. Where I ride in the hill country of south Texas, that means sitting by the road side for hours waiting for the road side assistance which is not an option for me.
The OP can let most of the iare out of the tire; loosen the nut and if the valve stem can be moved up/down, there is a tube. Most will say running a tube in a tubeless tire is not a good practice as it over heats the tire