ILLUMINATION was set up and developed by Dr Mehmet Yildiz and is a fine publication for you to join.

As for all Medium publications, to become a writer for that publication you need first to apply using their own system for inquiry ... you'll find this if you click on the ILLUMINATION tag (found at the end of all stories published by them).

Or - you can simply type 'ILLUMINATION' into the Medium search, and go from there.

Once accepted, you'll be able to publish there whenever you have a new draft.

Good luck with your own efforts to spread your stories.

Fred