Ah, well, here we run the risk of the blind leading the blind because I only got it to work by stumbling (ass over head) through aimless tapping, repetition and pure chance with Jose’s words richocheting in my head. So, with that caveat, I believe I began by downloading FUTO Keyboard from F-Droid. (Search for ‘FUTO’) and you should see ‘FUTO Keyboard’ and ‘FUTO Voice Input’. Install both. Then, if you open FUTO Keyboard>Language & Models and tap on ‘Voice Input’, you can choose from available voice-to-text models (each optimised slightly differently). You may be taken to a webpage view when you can download the model you prefer. I had a few goes at this. Anyway, choose one and tap the ‘left’ arrow on your MK back to Languages & Models section again. It should now show ‘Externally imported model’. I’m not sure if you need to have ‘Transformer’ set to English v1 but mine is now selected and it works. I had many failed attempts where I believe it wasn’t selected. Throw in a few handset restarts and that should get you either close to victory or to the point of frustration. I’m sorry I can’t be definitive. Someone eminently more qualified than me can probably provide a better guide.
Cheerio.
PS. I nearly forgot – for some reason the F-Droid version of FUTO Keyboard didn’t play well with the F-Droid version of FUTO Voice Input. In desperation I downloaded FUTO Keyboard from the Aurora Store and it worked. Coming from iOS, this Android world is a dizzying roller coaster.