Next.js protect login page from authenticated users

I want to redirect logged in users back to the application when they visit the login page.

I used to be able to call

const { user } = await getUser(ctx);

const { user } = await getUser(ctx);

const { user } = await getUser(ctx);

const { user } = await getUser(ctx); from gSSP but that's no longer possible. How can I achieve this with the latest version?