When react-router built Single-page application, how did it organize the login registration page?

  node.js, question
  1. Describe your problem
    I want to use react plus react-router to make a Single-page application, but I don’t know how to organize the login and registration interface. Should I make a separate page from Single-page application, or as a component of Single-page application, if the latter is the case, where should I put the component? Can the great gods offer the codes written by Nimeng for my reference? Thank you, happy new year, everyone ~

  2. Attach relevant codes

  3. Post error message

  4. Attach relevant screenshots

  5. What methods have been tried and still have not been solved (with relevant links attached)

Some of the official examples have not been referred to:
Auth-flow and auth-with-shared-root