Hi,
Once the plugin is installed it should ideally appear on the dashboard page or in the right region of the dashboard page (Sidebar). If you are not able to locate the site monitor block it might be because the plugin was installed properly on your end. Try to install the plugin from Moodle site > Site administration > Plugin > Install plugins
Please note that you need to have write access to blocks folder for the plugin to be installed correctly and the to have Edwiser Site Monitor working error-free please make sure that your site has a cron set up and uses the dedicated hosting instance and not a shared hosting instance.