After a Module is installed by Composer, it needs to be enabled to Drupal.

Using the Extend link on the Administrative Tool Bar.

Enter the start of the name of the new Module in the Filter box.

This will find the Module much faster than scrolling down the page.

Once the Module iss found, check the checkbox and save,

After the Module is enabled.  Go back to the Module and see if any configuration is necessary by clicking on the Module.