What exercise or gymnastics do you do?

Question

Health and computer

Frequent back problems. Pain.
Because of work, sometimes you have to sit for 18 hours at the computer.
What exercises are there, maybe a complex to be in shape, preferably on the back.
There are 2 dumbbells of 2 gk each and another weight of 14 kg. Preferably using them.

Answer 1

Because of work, sometimes you have to sit for 18 hours at the computer.

And you don’t sit for 18 hours in a row, at least once an hour you need to get up and leave for 5 minutes, save your back and eyes.

Answer 2

The Samsung Health (S-Health) app has a large number of different programs and courses, everything is free, there are programs for both the back and using dumbbells. Just for charging 10-30 min. You don't need a fitness tracker.
PS Smart any, not necessarily Samsung.