Here is a list of largest volunteer funds at your disposal (military and non-military help):

Come Back Alive ex. These guys delivered first deep-strike drones

https://savelife.in.ua/en/donate-en/

Serhiy Prytula Charity Foundation ex. Bought a famous spy satellite

https://prytulafoundation.org/en

KOLO Charity Foundation managed by UA tech community

https://www.koloua.com/en/