Edit: it looks like there is a voice input only app they make that is separate, that is what I use. https://voiceinput.futo.org/
Did you mean "but"? Helioboard is a full-blown keyboard if I remember, and FUTO is offline voice LLM only, with multiple language support. I only speak English but it works great. It's not a keyboard that types, you just click it when you want to speak.
I see they have a multilingual version, but is it possible to set it to use only English and one other language? SwiftKey does that and it works great.