Remote Management Removal

If you’re device is enrolled in a managed deployment, then only the person who has admin rights and access to the MDM server can in-enroll that device for you. That’s the whole point of MDMs - they take away user control so the company can manage devices via the deployment profile. That also means a user cannot un-enroll their own device.

So you’re going to have to ask your past employer to remove that device from the company deployment. There is no other solution.

That would need to be removed by the company that installed it on the iphone.

And the answer still doesn't change the company needs to remove it, contact the company.

that should've been removed when you parted with the company.