I tried this and it doesn't really do the job yet it seems to be a work in progress it doesn't enable voice input in Firefox for any box. The default settings will always use your speech input to do a search on DuckDuckGo, which works well and pretty seamlessly. however if you're going to use this for speech input for anything else it's not really a finished product. You have to disable the auto search setting and then use your mouse to click on the microphone and then click on the transcriber function and when the speech is recognized then press the copy function and then go into your text box and use control V to paste the transcribed text into your text box. I'm using the extension to type this comment now. This is way too many steps and keyboard mouse inputs at this time. Why not just recognize the speech and type it into the focus point of a text box in one step? Needs more work.

"Preparing microphone" c’est tout ce que ça me dit