There is no fMRI involved anywhere here.
You should be able to download the .zip file that Thomas sent.
Create a new protocol, copy all the files in the package to the anat/@default_subject folder.
Then in Brainstorm, right-click on (Default anatomy) > Reload.
After that you should be able to use this as an anatomy template for estimating sources for your MEG recordings. If you have access to the head shape of the subjects, you would improve the source localization by warping the template to the head shape of the individual subjects.
https://neuroimage.usc.edu/brainstorm/Tutorials/TutWarping