If you see the company portal that means that you bought the phone from someone or some company that it belongs to. It is most likely under Apple Business program and therefore the company who owns it will need to release it from the Apple Business Manager.
You might want to reach out to who ever you bough the phone from to see if they can do this for you.
Release devices in Apple Business Manager
https://support.apple.com/en-ca/guide/apple-business-manager/axmec4d28461/web
Remove devices by using wipe, retire, or manually unenrolling the device
https://learn.microsoft.com/en-us/mem/intune/remote-actions/devices-wipe
If this is helpful please accept answer.