OK,
Start with the easy bits.
jack up the mower both rear wheels off the ground and work the pedals.
If the wheels move then stop the mower and remove both wheels.
There is a length of 1/3 key steel in both axels if one has sheared then the mower won't move
They are part No 2 in this diagram
https://www.partstree.com/parts/husqvarna/mowers-lawn-garden-tractor/yth-2348-96045002201-husqvarna-yard-tractor-2010-04/drive/,
Also check that the belt is on the rear pulley and not sitting between the pulley and the fan
If neither of these are the problem then locate the stabilizer at the front of the transmission.
It might be a strap or a couple of bolts joining the front of the tranny to the frame, check that these have not sheared or the mounting bent allowing the transmission to cant foreward & down.
Other than that, support the mower on jack stands and get an assistant to release the brake & work the drive pedal while you are under the mower watching & listening.
Use 2 stands either side of the frame and not one on the tow mount