Several countries’ governments have accused the Israeli government of genocide and asked the International Criminal Court to prosecute Israeli officials, but that court answers to the U.S. government and has refused for years to prosecute crimes by Israel or anyone else outside of Africa.
But the International Court of Justice has ruled against Israel in the past, and if any one nation invokes the Genocide Convention, the court will be obliged to rule on the matter.
If the ICJ determines that genocide is happening, then the ICC will not need to make that determination but only consider who is responsible.
This has been done before. Bosnia and Herzegovina invoked the Genocide Convention against Serbia, and the ICJ ruled against Serbia.
The crime of genocide is happening. Eliminating even part of a group is genocide. The law is meant to be used to prevent it, not just review it after the fact.