You need to define the range and precision that you are seeking.
As its a 10kg load cell I’d assume you need to measure in the range ± 10kg. (or 0 - 10kg)
You havent linked to the load cell spec so we dont know which you are using.
I’d expect you have used the HX711 red, black, white green and yellow connections to your load cell as that provides a very stable excitation supply to the load cell.
And the board has on-board smoothing and decoupling for the psu.
So what sources of noise are left? Well you could have a noisy load cell; or noisy connections (you HAVE soldered them I hope?)
Then vibration and draughts could affect your readings.
So what is the precision you need? Do you need a result that is accurate to 1g?
And what readings are you getting - for zero, and with a test weight (eg 1kg) added.
You can add a little hysteresis in your program to reduce the effects of noise.