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Hello! You can't access the application page until you've been a member on the forums for at least 45 days, linked your minecraft account to your profile account (use /link in the lobbies), made at least 20 posts on the forums, and 50 accepted player report tickets. Keep in mind that these are not the only requirements to become a staff member, but they are the requirements to be able to read/submit an application. After all 4 of these have been fulfilled, you should be able to open the staff application page without being redirected to the mcc homepage.

Hope this helps, have a great day!