Mini steppers

I have a set of kettler steppers. They are hydraulic and I can get a good bit of exercise on them. They do require force, which reduces as the oil inside gets moving. I keep mine in the kitchen, they are small and I have that handy worktop for balance. I find they exercise my leg muscles and my heart and lungs, just what I needed over winter, until I could get out cycling again

Mine are old now and I will never get rid of them. Not adjustable

I don't know if it's what you mean but I had a set of what seem like floor mounted bicycle pedals. I could just pedal away while sitting in my chair. The resistance could be increased. I got them from Amazon after my first knee replacement. Maybe not what you mean though. Other than that I used our stairs as my gym.

Thought I'd bump this up as surely someone will have ideas.