Best way to reach Immenstaad

Hello, I have a work thing in Immenstaad in June. I'm flying from the Middle East so my visa will allow me to land in Germany only (I can't come through Zurich airport).

I had come to Immenstaad once before and I usually take a connecting flight to Friedrichshafen through Frankfurt. But right now, I'm checking all the flight schedules and I can't find any flights from anywhere in Germany to Friedrichshafen.

I'm open to using the train/bus as well. Any recommendations or tips will appreciated. Thanks.