You can remove the remote management supervision iphone by resetting the settings on the iphone. However if the supervised mode is enabled via apple configurator it will work. In some cases this doesn't work meaning your iphone is supervised automatically using apple business manager. The only way to remove supervision is by resetting your iPhone to factory settings. But this is not a simple procedure, as you'll need to use a computer to follow the instructions.
If the supervised mode was enabled via Apple Configurator, you'll need to delete the supervised user and create a new one. This will remove the remote management iPhone supervision.
If the supervised mode was enabled via Apple Business Manager, you'll need to contact Apple Business Manager support to remove the supervision. This is because the management profile is stored on the server and can only be removed by Apple Business Manager support.
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