After you install the KWizCom modern apps in your tenant, as a site admin you need to install the required apps in your site to make them available to users.
1. Click the site's gear icon and select "KWizCom Apps Settings":
2. In the KWizCom Apps settings page, install all features by clicking the "Install all" button:
You can also install only selected features by clicking the toggle button 
available next to each feature.
After you install all/selected features you will see the installed ones showing active (and not grayed):
After the selected features have been made available in the site, you can activate the KWizCom apps in the relevant lists and libraries and then start using them.