I created a step challenge as private, but I would like to change it to public so that it's easier for friends to join. Some are having issues joining with the email invitation.
Great question. If you were the one that has created the challenge you should be able to change the option in the challenge settings from private to public. If this does not work I would suggest recreating the challenge and making it to public.
Where do i find the challenge settings?
Should be under the challenge you have created. If not, again, I would suggest recreating the challenge and making it public.
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