Missing the button of "Request Join" in the context of "Wiki Index"

I want to join a Wiki following the official document posted here as quoted below.

In the context of “Home > draw down list > Wiki Index”, there are columns of “Name”, “Description”, “Owner”, “Creation Date”, “Membership Type”, and “Actions”. However, the “Actions” column contains the buttons “Edit” and “Delete” but no “Request Join”. So I cannot make the request.

And I don’t think it’s a permission issue because the username has admin permissions.

I will highly appreciate any hints or suggestions.

Quote the official document page:

Steps to reproduce

Preconditions:

  • Create the SubWiki with admin or a global user that has wiki creation rights;
  • The SubWiki joining policy must be configured to: ‘Any global user can request to join but an admin must accept’
  1. Log in as a simple user
  2. Click on Drawer > Wiki Index
  3. Click on “Request Join” in the corresponding Actions column
  4. Write a message
  5. Click on “Send Request”

Expected results

A confirmation message is displayed that the request has been sent.