How to encapsulate react application?

Question

JavaScript

Hello! Can you please tell me what are the options to encapsulate a react application?
There is a react application and it needs to be rendered on another resource. Everything works fine when I just include the file with the bundle. But in this case, there is a problem with styles, this site uses a lot of !important .
I thought about the Shadow dom solution , but there is a problem with the events plus the performance is deteriorating. There is also an option with an iframe, but I don't want to use something.
The question is, what other options are there to encapsulate the application?
I will be grateful!