Unfortunately, this feature is not currently available. At this time Apple does not provide a dictation platform for third-party keyboards, but this is something we are hoping to be able to integrate in a future version.
A solution to get around this issue is to keep the stock iOS keyboard available when you would like to use dictation. Unless you have deleted the stock keyboard, it should be accessible by tapping the emoji button (smiley) next to the 123 key on the keyboard.
If you have deleted the stock keyboard, you can re-enable it by:
- Enter settings on your device.
- Tap on ‘General’.
- Scroll down to ‘Keyboard’.
- Tap on ‘Keyboards’.
- Add your stock keyboard by tapping ‘Add New Keyboard’ and selecting the language(s) of your choice.
If this is an important feature to you, please let us know by submitting a Feature Request [here].