I need the Port out PIN

I have tried to use the Xfinity App to generate the port-out PIN multiple times, but it always says " looks like you don't have Xfinity Mobile service."    I tried the online chat, but they couldn't help and suggested calling the service number.  Called the service, but he cannot do it either.    I have been trying to port out for 2 days and still have no clue how to move forward.  Can anyone help?

The mobile line is linked to my current account, which will be closed soon.  I have a new account for a new plan, but it hasn't been activated yet. Everything is blocked due to the port-out PIN.