Translation:
Remove Remote Administrator
I bought an iPad owned by an external administrator. The company that once managed the iPad no longer exists and is no longer registered. Now I want to get rid of the management, the iPad has been reset in the past but never deleted from the environment of the company. How can I get the management off? I only get to a login screen of this company.
The presence of a management profile indicates that the device is centrally managed by an Enterprise or Educational establishment. Devices that are configuration locked by an MDM platform can usually only be released from central management by the platform that manages the device. Be aware that Apple will not assist with removal of management profiles.
Unless you are lucky - and have the option to delete the profile from iPad Settings - you’ll need to seek assistance directly from the System Administrator who manages the device.
Install or remove configuration profiles on iPad - Apple Support