First of all,
what was the output of:
conda create -n env3-10-complex -c conda-forge python=3.10 fenics-dolfinx petsc=*=complex* mpich
Secondly, how are you running jupyterlab?
Thirdly, does the installation of petsc work if you run from commandline?
Finally see: How to set up a Conda environment with a Jupyter kernel | by Yara Kyrychenko | Medium