For group analysis, save evoked data in BIDS-derivatives:
from mne_bids import write_anat write_anat(bids_root, subject='001', t1w_anat='sub-001_T1w.nii.gz') Assuming you have one evoked response per subject per condition: mne bids pipeline
Save source estimates in BIDS derivatives using mne-bids : For group analysis, save evoked data in BIDS-derivatives: