Decree Absolute is received, worried that ex will provoke me or damage the house

Hi all,
My situation:
I have divorced, Decree Absolute is finally arrived by end of August 2020.
We have a son, he is 6 (almost 7).
There are no court order for child arrangements.

I have a flat (1 bedroom), bought prior the marriage; mortgaged on my name, ownership solely on my name (title deed only me). Three of us lived in 1 my flat.

Ex has registered "home rights" on my flat with Land Registry, while the divorce was on going.

She is Lithuanian (not British); she has property in Lithuania solely on her name.

As divorce is finalised, I am afraid that ex would provoke me, or she might damage my belongings or the flat.

I feel really scared.
I have read about "occupation order", but I don't understand how to complete that form. I am happy to live with my son, but I don't want her to be in my house.

What can I do?

Thanks