There are few hotfixes/patches which will not be listed in the patch tuesday updates from Microsoft. Customers have to request Microsoft directly for these hotfixes/patches. Since they are not publicly listed, they will not be available in the online patch repository of Endpoint Central MSP and hence cannot be installed using the patch management module. These hotfixes/patches can be deployed using software deployment module of Endpoint Central MSP.
The following steps will guide you to install the msu through software deployment.
You can select the package and click Install/Unistall software button and choose the computers/users to deploy the hotfixes/patches using software deployment.