https://wildfiretoday.com/2022/01/17/hunga-tonga-volcano-tri...: “a ground-based lightning detection system recorded nearly 400,000 strikes with 200,000 occurring in a one-hour period.”

Lightning causes EMPs (https://en.wikipedia.org/wiki/Lightning#Transient_currents_d...) , so there were EMPs. I think/guess each one was a lot less powerful than that of a nuclear explosion, though.

I don't think Vulcanoes usually produce an EMP, however, we did record quite a number of lightning strikes around the vulcano. If memory serves, the area around the vulcano was struck in excess of 200'000 times per minute at the height of the ejecta's activity.