https://www.greatbiblestudy.com/deliverance-ministry/demonic-legal-rights/
The process of deliverance often consists of three main parts: Tearing down strongholds, removing legal rights and then casting out the remaining demons. If you try to cast out demons without taking away the strongholds or legal rights that they are holding onto, then you can’t really expect to achieve a complete successful deliverance. Removing these two blockages is vital in going about a complete and successful deliverance.

demons cannot enter into a person’s body without having some kind of legal permission and legal right to be able to do so. They need some kind of an entry point to be able to get in and attach to someone, and that entry point will be their door opener.

https://www.bible-knowledge.com/dealing-with-the-legal-rights-of-demons/