Find My is only disabled if you prevent activation lock (in the pre-stage policy) or prevent users from using Find My (restrictions profile).
If you have ABM and you are using automated enrollment, then you simply need to put the device into Lost Mode. This will lock the device and send GPS information to the MDM so you can locate the device.
In Mosyle, select a device. When the Device details popup appears, press the More button and select Activate "Lost Mode." Complete the form and submit the command.

Optionally, you can play a sound to locate the device.
Note, when you recover the device, you will need to use Mosyle to issue a Deactivate "Lost Mode" command. Unlike a Mac, you do not have an unlock pin.
Also, before this Summer, it was critical to prevent users from enabling Activation Lock as getting the device removed required a call to AppleCare and presenting proof of purchase. Since this summer, you can now remove activation lock one DEP devices in ABM. This is a great feature added by Apple. This means that if you have a DEP device and you allow users to login with personal Apple IDs, and the user enables Find My... When they leave and return the device with activation lock enabled (linked to personal Apple ID), you will not need to beg them to sign out. Simply log into ABM and release the Activation Lock.
Hope this is helpful. If you have not rolled out the devices yet I strongly encourage you to familiarize yourself with Mosyle and all the options available. You should be creating test enrollments and validating your deployment workflow as well as the end users workflow and use cases.