Added plugin to project on this site. Checking project Updates section - got 1 update about this plugin. Click install, all seems going well, installation is completed but no new plugin appear in Updates list

October CMS has not yet been install dependencies automatically (for details, see https://github.com/octobercms/october/issues/36).

Microblog plugin is dependent on the RainLab Blog plugin. Install it and all will work.

I did what thewizardplusplus said, and it worked.