How to: Install a Lightweight Add-On on an On Premise server

Browse to your Business One server’s SLD (Capitalization of ControlCenter is mandatory), https://LOCALHOST:40000/ControlCenter/ or https://SERVERNAME:40000/ControlCenter example https://onprem:40000/ControlCenter
then your Extension Manager (Capitalization of ExtensionManager is mandatory)
https://LOCALHOST:40000/ExtensionManager/ or https://SERVERNAME:40000/ExtensionManager/ example https://onprem:40000/ExtensionManager/

For older servers use 30010 instead of 40000
Log in using your B1SiteUser username and password

Click the Import button to start the import process
Click Browse and locate the Add-On zip file and select it. Then click Upload.
Once uploaded click Next twice
Here you will need to assign the Add-On to a company database. To do this click the “Finish import and run the company assignment wizard” link.
Select the company you wish to assign the Add-On to and click Next twice
Select your default startup mode and/or select the startup mode for individual users in the database.
Click Finish or click the link to run the company assignment wizard again to assign to additional company databases.