Hi @amyrmkm
Perhaps may not be the sudo, but the fmriprep-docker command. By chance when checking paths it could be something with environments. May you please try following this? Another thought is that fmriprep-docker has not been downloaded (rather pulled fmriprep directly) so it would make sense that the command is not found. The linked post comment is using pip vs docker to get the fmriprep-docker tool