Here are some organizations that may have volunteering opportunities in Israel.
Leket (harvesting, sorting & distributing food for the needy); Hospitals (e.g., Hadassah) and a special program organized by JNF-USA. Almost half of all Israelis volunteered in the first two weeks of war.
https://www.israel21c.org/half-of-all-israelis-volunteered-in-first-2-weeks-of-war/