Go to your Google Admin Console (at admin.google.com)
Go to "Devices"
Click "Apps & extensions"
On the left, select the organizational unit where you want to configure settings
Hover over the add icon
Click on"Add from Chrome Store" icon
Type the app name in Search the store bar and hit enter
Click on "Select"
Click "Installation policy"
Choose "Force install" or "Force install + pin"
Click on "Save"