There are several options for provisioning into any fully managed deployment scenario (COBO, COPE, COSU):
NFC (5.0+): With the use of a provisioning app provided by your EMM of choice on a spare device, simply input basic environment details and bump NFC radios with a freshly factory reset (or brand new out of box) device to begin provisioning.
Managed Google account (6.0+): Begin setting up a device as normal (including connecting to a network) and at the Google account prompt, enter the managed Google account (G Suite, Google Cloud Identity) address and authenticate as normal.
DPC identifier (6.0+): Begin setting up a device as normal (including connecting to a network), but at the prompt to enter a Google account opt instead to input the DPC identifier of your EMM, plenty of examples are available here.
QR code (8.0+): With a QR code provided by either the EMM solution or a counterpart provisioning app (the same potentially used to provision via NFC), simply tap 6 times on the welcome screen to be download the QR reader (8.0) or switch to it automatically (9.0). WiFi details are required unless provided within the QR for 9.0 devices.
Zero-touch (8.0+): Devices purchased through an authorised reseller may be assigned to a zero-touch customer account, and with a configuration created and assigned the device with automatically begin zero-touch provisioning as soon as network connectivity is established.
KME (Knox 2.8+): Samsung devices running Knox 2.8 or above are compatible with Android Enterprise provisioning via KME. Devices added to the KME portal with a profile assigned will begin KME provisioning from a factory reset state.
Other: Your device OEM may support other methods of provisioning. Reach out to them to request details.