One way is to donate to charities and NGOs that are working on the ground in Ukraine. Go to https://www.koloua.com/en or https://u24.gov.ua/.
These organizations are providing much needed aid to those affected by the war, such as food, shelter, and medical care. Another way is to volunteer with local organizations that provide assistance to those in Ukraine. You can also support Ukrainian businesses and organizations by purchasing their products and services, or investing in them. Finally, you can spread awareness of the situation in Ukraine by educating others on the issue and engaging in advocacy campaigns to raise awareness and encourage action.
However, no matter how you choose to help, your efforts will be greatly appreciated and will contribute significantly towards the rebuilding of Ukraine.