why in my wordpress admin panel the membership option is not showing

This setting is not visible on individual sites in a Multisite Network. Instead this setting is set at a Network level on the Network Admin Settings Screen.

If you need to control this setting per-site, see this previous question on the topic.

Hata!: SQLSTATE[HY000] [1045] Access denied for user 'divattrend_liink'@'localhost' (using password: YES)