Depleted utanium is a war crime

Actually, it's not. Quoted from the British article about the DU rounds they're shipping for the Challenger 2s:

The UK MoD insists that the depleted uranium shells it is sending to Ukraine are not prohibited by any international agreement.

It says that under Article 36 of the First Protocol of 1977 Additional to the Geneva Conventions of 1949, the UK's depleted uranium shells are "capable of being used lawfully in international armed conflict".

President Vladimir Putin has warned that if the UK does send depleted uranium shells to Ukraine, "Russia will have to respond accordingly, given that the West collectively is already beginning to use weapons with a nuclear component".

The MoD replied in a statement: "The British Army has used depleted uranium in its armour-piercing shells for decades. Russia knows this, but is deliberately trying to disinform."

Stating the use of DU is a war crime is just Russian mouthpieces repeating Kremlin lies.