You may know this, but some of them lawnmower, lawn tractor rims have the tubeless valve stem mounted in a location on the rim that a inner tube valve stem will not align with when the tube is inflated. Have to drill a hole in the proper location for the inner tube stem and then sometimes this will also place the valve stem on the inside of the rim when mounted on the mower. Place a piece or tow of duct tape over the removed tubeless stem hole.
Inner tubes are not cheap now days and labor involved installing one is sometimes sweaty and disgusting.
I try to use the Carlisle brand inner tubes and a straight stem is a TR13. I think the bent stem is TR87.
I tried some of the cheaper inner tubes from flea bay and they are not worth the effort. Usually the rubber is too hard and they will split easily when air is added.