Anti-spin rear axle is available for any of the gears including the 3.21 based on the 2019 Build & Configure on RAM's web site. For the 3.92 gears it looks like those are only available for the Hemi-equipped units.
The Electronic Locking rear axle is a different option and requires one of 3 different options to be selected - 3.92 gears, Off-Road group or North Edition.
So if you want the Electronic locker then you need a Hemi-equipped truck with the 3.92 gears. If the anti-spin is good enough then any gear and any engine option will work.
TT: 2019 ORV Timber Ridge 23DBS, Blue Ox SwayPro 15K/1500
TV: 2019 Ford F-250 XLT SuperCab LB, 6.2L, 4.30/e-locker, 4x4, 164" WB, 3216 payload
TV: 2014 RAM 1500 Big Horn CC (Traded in)
TT: 2015 Jay Flight SLX 195RB Baja Edition, Andersen No-Sway (Traded in)