Hi Mohammad Zalabany,
Sorry to hear you’re having an issue.
We have checked this for your account,
You have joined “10 Week Challenge” successfully.
This button on the “Profile” section is enabled to participate in the challenge by adding your check in with before pictures.
That button is changed with Right tick that indicates the you have joined the challenge successfully.
Button has disabled from the “Profile” section now as the Joining time has expired.
Do let us know on firstname.lastname@example.org if you have any further questions and we will help guide you through.