Because this is an enterprise-grade product, it is not available for direct public download through the standard Microsoft website or Media Creation Tool. You must use one of the following official channels:

You need a client key or a MAK (Multiple Activation Key) from your volume licensing agreement. Public “generic” keys exist for evaluation but will not activate the OS permanently. Example generic KMS key (for setup only – WILL NOT ACTIVATE): NPPR9-FWDCX-D2C8J-H872K-2YT43 (Do not use this for production. It only installs the product, not activate it.)

The 2016 iteration is particularly prized because of its "LTSB" status. In the modern Windows ecosystem, features are updated constantly. However, in an industrial setting, an update that changes the interface or breaks a legacy driver can cost thousands of dollars in downtime.