How to customize Swagger UI - add version dependent section

Question

I have an API with versioning implemented. I have a swagger document generated per API version. I am using the standalone bundle for the swagger UI.

I need to add some extra information based on the version currently displayed.

The desired place is to add an HTML block above the info section.

I am trying to integrate it directly into the index.html. I need to evaluate the version of the API being rendered.

Is there any action I can override by a custom plugin?

I tried to create a plugin following the documentation https://swagger.io/docs/open-source-tools/swagger-ui/customization/plugin-api/ but I do not know what I should use for that.

Any ideas are appreciated.