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/

Razom Ukraine (US based) https://www.razomforukraine.org/