We have 120 machines that are part of our Apple Business Account, but were enrolled into Jamf with the web browser, and are considered a "user initiated enroll". As such, we are unable to push out certain commands to these, such as the update commands. These are all company purchased machines on our Apple business account, they were just enrolled through the browser.
How can we force these machines to get on DEP?
I should also ask why these Macs didn't go through Automated Device Enrollment when they were initially set up? You mention having them in ABM, but have you connected your Jamf Pro instance to ABM, and configured a PreStage Enrollment all of your Macs (or at least the ones you want to do ADE) are assigned to?