I used to have Confluence access, but now I don't, as shown in the screenshot.

[Zihao_Guo]

I used to have Confluence access, but now I don't, as shown in the screenshot.

[Trudy P Claspill]

Hello @Zihao_Guo 

Welcome to the Atlassian community.

This is a user community. We don't have access to manage your access to that Confluence instance.

You will need to contact the administrators of that instance to get assistance. If you are not sure who that is I recommend you start by contacting the people that originally told you to access that Confluence instance.