I would use the Conda package for Julia to check that you have the jupyter package installed.
import Conda
Conda.add("jupyter")
Conda.update()
Conda.clean(; sources=false);
I believe that quarto just needs the environment variable QUARTO_PYTHON
set to, in your case, "Users/ronnber/.julia/conda/3/bin/python3"
but, as you say, frequently there are so many different versions of Python and Conda and pip floating around that things get confused.