The Application Manager Integration Client must be installed somewhere on your internal network.
Integration Client Requirements
Operating System: Microsoft-supported versions
Active Directory: AD domain joined
Microsoft .NET Framework: Version 4.x or later (ConfigMgr 2103 requires .NET Framework 4.7.2 or later)
Configuration Manager: ConfigMgr console including PowerShell modules
Disk space: At least 100Mb of free disk space for AM Integration Client
Permissions: Administrative level user account for installation
Disk space: SMB network share for storing downloaded application installer with at least 50GB of free disk space.
External Domains: Application Manager requires outbound access to the following addresses:
- amclients.recastsoftware.com (TCP/443)
- recastampackages.file.core.windows.net (TCP/443)