Regarding by default Modern interface

How can I access the old web interface after setting the modern interface as a default interface?

I have followed the steps

1. Build the modern interface with Home attribute = https://example.com in package.json
2. Change the path to ./web/modern/

You would probably have to modify some code.

Which code, can you please give me some direction?

You can't just change the path. You need to switch the two interfaces. Then you need to update all API calls that the old app does to match the new location.

ok. Now I understood.

Thank you