Braille input alternatives for people with less than three fingers per hand

I would like to know what braille input alternatives exist for blind users who do not have all of their fingers. I am interested in both software and hardware methods implemented in assistive technologies in mobile phones, computers, and braille devices.

I was thinking that perhaps, a device could be configured to use two buttons, one to accept and one to reject dot x, where x goes from 1 to 6, so that a character can be input with a single finger with six presses. Further buttons could allow the user to navigate back and forth between letters, delete letters, before or after the cursor, and send. Ideally, the device can be configured to the number of fingers that the user can use. Can a Braille device be configured to work in this manner?

What alternatives exist, and what are some of the ways in which this can work. These configurations could probably also be good for blind users memorizing the braille patterns corresponding to letters in a blind braille app on Android, or on TalkBack braille input.

I don't know if TalkBack braille input, or perhaps even Google Assistant, when asked "teach me Braille", can provide such functionality in a tutorial.

I think it would be nice. Students could first learn braille with one finger, and then, only if possible, using multiple fingers.

The tutorial would first teach about the existence of dots one to six, and, only then, in a second tutorial for people with three fingers or more per hand, teach about the dot positions, such as dot 1 is in the upper left, dot 2 is in the upper right, dot 3 is in the middle left, for 4 is in the middle right, dot 5 is in the lower left, dot 6 is in the lower right. This is the braille configuration the dots use, as far as I know. So then the user can proceed with left ring finger for dot 1, right ring finger for dot 2, left middle finger for dot 3, right middle finger for dot 4, left index finger for dot 5, and right index finger for dot 6, and proceed (possibly using the index fingers ad control fingers).

How would braille input work if less fingers were available?

Thanks you for your responses.