Hi all! Thank you Alexey! Everything works now.
Now I wonder why our DIY pedals have apparent interference noise? As I see from your, and other guys videos, you have that too. When I watch videos from Sim Racing Garage, all proffesional pedals look so smooth on their calibration screens. They are not using special cables or connectors.
I used 0.22uf capacitors at first, there was heavy noise. I kept searching about noise and found that information on a forum: Now I use 100uf caps: https://electronics.stackexchange.com/questions/591849/minimize-load-cell-amplifier-noise-and-interference-ina122p
I also tried 47uf, 470uf and 1000 uf. But after 100uf, there was not a noticeable improvement. So I kept 100uf caps on all 3 pedals.
Video of my calibration screen (clutch pedal is dismounted. Axis 1 throttle, axis 2 brake): https://drive.google.com/file/d/1Ae_bYKV_8YsdbNuA9ggUdfZYK7rfo_F4/view?usp=sharing