I understand that M26 ammo can’t be sent without an act of Congress because they are cluster munitions and since there has been no such act then at least the US hasn’t delivered them.
I think the US avoids cluster bombs now and that is why ball-bearing munitions such as the M30A1 missiles were designed.
The Ukrainians have received the M30A1 missiles with 182,000 ball bearings each, to destroy troop masses and soft vehicles.