You can probably do it with a keyboard paired to a server/RPi that emits the keystrokes to the Roku ECP API, if having that second device is acceptable.
On my rokus, I am able to use my phone as a remote via the roku app. This includes typing on mobile via my phone's keyboard. Makes logging into things much easier.
AppleTV is like that too. It's nice being able to use the password manager on my phone rather than have try to enter some long complicated password a letter at a time.
You can probably do it with a keyboard paired to a server/RPi that emits the keystrokes to the Roku ECP API, if having that second device is acceptable.
On my rokus, I am able to use my phone as a remote via the roku app. This includes typing on mobile via my phone's keyboard. Makes logging into things much easier.
AppleTV is like that too. It's nice being able to use the password manager on my phone rather than have try to enter some long complicated password a letter at a time.
Rokus have a rest api that accept all the navigation and text inputs you'd do with the remote.
This might be possible now. I think the better option is having a hardware device that acts a bridge between a bluetooth keyboard and the Roku.