MERN : Several Design templates and renderFullPage()

Hello fellow developers.

I am new to Node.js and MERN

Lets assume we have several layout pages. My web app has /login /register /dashboard routes. and /dashboard is using default mern starter example layout, which is enough for me to start my project, BUT... /login /register completely differs from layout in renderFullPage().

My problem is "how to" render another HTML layout based on route (/login /register)?

Thanks in advance