Update your app. You cannot choose an artifact until you are on 1.140 for the Live worlds. The android update just came out today. I was on 1.139 and could not use it, updated, and and it works now.
@Marindor @Enevhar Aldarion
Thank you very much and yes, I haven't had the actual app version. Now with update to 1.140 everything looks fine.
Sorry for circumstances.