Follow the link above for more details on how you can support Ukraine.
If you want to learn more about russian warcrimes in Ukraine you can check out russian war crimes you can also check out Bellingcat's Civillian Harm in Ukraine which is updated regularly.
There is an active investigation ongoing by the International Criminal Court in the Hague.
Below are a couple of ways of maximising the efficiency of your donation rather than donating through a bureaucratic organisation like the International Committee of the Red Cross (ICRC)
Come Back Alive - Organisation based purely on supplying the Ukrainian Army and volunteer forces with defensive equiptment, technology, and training. The emphasis is on saving lives and the organisation does NOT purchase lethal equiptment. They offer card payment options through Fondy.eu, crypto payments, and SWIFT payments.
U24 - Initiative by the President of Ukraine - A streamlined website as part of the United24 initiative by the President of Ukraine Volodymyr Zelenskyy. Offers card, crypto, SWIFT, and PayPal payment options that can be directed explicitly at one of three main funds: Defence and Demining; Medical Aid; Rebuilding Ukraine.
National Bank of Ukraine - Armed Forces fund - The official account of the National Bank of Ukraine through which you can send funds directly to the UA government / Ukrainian Armed Forces without any intermediaries. They offer card, crypto, and SWIFT payment options. They also offer distinct EUR, GBP, USD, and JPY accounts and have IBAN's listed for all of them, but you can use standard domestic transfer options if you live in one of those countries.
National Bank of Ukraine - Humanitarian fund - The official account of the National Bank of Ukraine through which you can send funds directly to the Ukrainian Ministry of Social Policy without any intermediaries. The fund will be used to provide shelter, food, and clothes to those displaced by the war in Ukraine. They offer card, crypto, and SWIFT payment options. They also offer distinct EUR, GBP, USD, and JPY accounts and have IBAN's listed for all of them, but you can use standard domestic transfer options if you live in one of those countries.