How do I remove next dns from my iPhone if I prohibited it.

Hello, a few months ago I turned on prohibit deleting (I think that’s the options name) when installing it to my iPhone  I now don’t want it as a site I use regularly says that I have to disable my Adblock which I don’t want to keep disabling it and would be easier if I just removed it  but after updating my phone it is no longer supervised nor can I find a way to remove the profile. Can anyone help me?

all help appreciated

thanks

Kieran